Ensure that the focus ring in the bookmarks bar does not paint outside the parent view.

ui/views/controls/scroll_view.h

Index: ui/views/controls/scroll_view.h
diff --git a/ui/views/controls/scroll_view.h b/ui/views/controls/scroll_view.h
index af9111a05cae1a2dd25daba64afe629560c7751e..0dea574a81bc1462a0f209c771f7514c570fc1f6 100644
--- a/ui/views/controls/scroll_view.h
+++ b/ui/views/controls/scroll_view.h
@@ -1,282 +1,299 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef UI_VIEWS_CONTROLS_SCROLL_VIEW_H_
-#define UI_VIEWS_CONTROLS_SCROLL_VIEW_H_
-
-#include <string>
-
-#include "base/compiler_specific.h"
-#include "base/gtest_prod_util.h"
-#include "base/macros.h"
-#include "ui/views/controls/scrollbar/scroll_bar.h"
-
-namespace gfx {
-class ScrollOffset;
-}
-
-namespace views {
-namespace test {
-class ScrollViewTestApi;
-}
-
-/////////////////////////////////////////////////////////////////////////////
-//
-// ScrollView class
-//
-// A ScrollView is used to make any View scrollable. The view is added to
-// a viewport which takes care of clipping.
-//
-// In this current implementation both horizontal and vertical scrollbars are
-// added as needed.
-//
-// The scrollview supports keyboard UI and mousewheel.
-//
-/////////////////////////////////////////////////////////////////////////////
-
-class VIEWS_EXPORT ScrollView : public View, public ScrollBarController {
- public:
-  static const char kViewClassName[];
-
-  ScrollView();
-
-  ~ScrollView() override;
-
-  // Creates a ScrollView with a theme specific border.
-  static ScrollView* CreateScrollViewWithBorder();
-
-  // Returns the ScrollView for which |contents| is its contents, or null if
-  // |contents| is not in a ScrollView.
-  static ScrollView* GetScrollViewForContents(View* contents);
-
-  // Set the contents. Any previous contents will be deleted. The contents
-  // is the view that needs to scroll.
-  void SetContents(View* a_view);
-  const View* contents() const { return contents_; }
-  View* contents() { return contents_; }
-
-  // Sets the header, deleting the previous header.
-  void SetHeader(View* header);
-
-  // Sets the background color. The default is white when scrolling with layers,
-  // otherwise transparent. An opaque color when scrolling with layers ensures
-  // fonts can be drawn with subpixel antialiasing.
-  void SetBackgroundColor(SkColor color);
-
-  // Returns the visible region of the content View.
-  gfx::Rect GetVisibleRect() const;
-
-  void set_hide_horizontal_scrollbar(bool visible) {
-    hide_horizontal_scrollbar_ = visible;
-  }
-
-  // Turns this scroll view into a bounded scroll view, with a fixed height.
-  // By default, a ScrollView will stretch to fill its outer container.
-  void ClipHeightTo(int min_height, int max_height);
-
-  // Returns whether or not the ScrollView is bounded (as set by ClipHeightTo).
-  bool is_bounded() const { return max_height_ >= 0 && min_height_ >= 0; }
-
-  // Retrieves the width/height reserved for scrollbars. These return 0 if the
-  // scrollbar has not yet been created or in the case of overlay scrollbars.
-  int GetScrollBarLayoutWidth() const;
-  int GetScrollBarLayoutHeight() const;
-
-  // Returns the horizontal/vertical scrollbar. This may return NULL.
-  const ScrollBar* horizontal_scroll_bar() const { return horiz_sb_; }
-  const ScrollBar* vertical_scroll_bar() const { return vert_sb_; }
-
-  // Customize the scrollbar design. ScrollView takes the ownership of the
-  // specified ScrollBar. |horiz_sb| and |vert_sb| cannot be NULL.
-  void SetHorizontalScrollBar(ScrollBar* horiz_sb);
-  void SetVerticalScrollBar(ScrollBar* vert_sb);
-
-  // Sets whether this ScrollView has a focus indicator or not.
-  void SetHasFocusIndicator(bool has_focus_indicator);
-
-  // View overrides:
-  gfx::Size GetPreferredSize() const override;
-  int GetHeightForWidth(int width) const override;
-  void Layout() override;
-  bool OnKeyPressed(const ui::KeyEvent& event) override;
-  bool OnMouseWheel(const ui::MouseWheelEvent& e) override;
-  void OnScrollEvent(ui::ScrollEvent* event) override;
-  void OnGestureEvent(ui::GestureEvent* event) override;
-  const char* GetClassName() const override;
-  void OnNativeThemeChanged(const ui::NativeTheme* theme) override;
-
-  // ScrollBarController overrides:
-  void ScrollToPosition(ScrollBar* source, int position) override;
-  int GetScrollIncrement(ScrollBar* source,
-                         bool is_page,
-                         bool is_positive) override;
-
-  // TODO(djacobo): Remove this method when http://crbug.com/656198  is closed.
-  // Force |contents_viewport_| to enable a Layer().
-  void EnableViewPortLayer();
-
- private:
-  friend class test::ScrollViewTestApi;
-
-  class Viewport;
-
-  // Used internally by SetHeader() and SetContents() to reset the view.  Sets
-  // |member| to |new_view|. If |new_view| is non-null it is added to |parent|.
-  void SetHeaderOrContents(View* parent, View* new_view, View** member);
-
-  // Scrolls the minimum amount necessary to make the specified rectangle
-  // visible, in the coordinates of the contents view. The specified rectangle
-  // is constrained by the bounds of the contents view. This has no effect if
-  // the contents have not been set.
-  void ScrollContentsRegionToBeVisible(const gfx::Rect& rect);
-
-  // Computes the visibility of both scrollbars, taking in account the view port
-  // and content sizes.
-  void ComputeScrollBarsVisibility(const gfx::Size& viewport_size,
-                                   const gfx::Size& content_size,
-                                   bool* horiz_is_shown,
-                                   bool* vert_is_shown) const;
-
-  // Shows or hides the scrollbar/corner_view based on the value of
-  // |should_show|.
-  void SetControlVisibility(View* control, bool should_show);
-
-  // Update the scrollbars positions given viewport and content sizes.
-  void UpdateScrollBarPositions();
-
-  // Helpers to get and set the current scroll offset (either from the ui::Layer
-  // or from the |contents_| origin offset).
-  gfx::ScrollOffset CurrentOffset() const;
-  void ScrollToOffset(const gfx::ScrollOffset& offset);
-
-  // Whether the ScrollView scrolls using ui::Layer APIs.
-  bool ScrollsWithLayers() const;
-
-  // Callback entrypoint when hosted Layers are scrolled by the Compositor.
-  void OnLayerScrolled(const gfx::ScrollOffset& offset);
-
-  // Horizontally scrolls the header (if any) to match the contents.
-  void ScrollHeader();
-
-  void AddBorder();
-  void UpdateBorder();
-
-  // The current contents and its viewport. |contents_| is contained in
-  // |contents_viewport_|.
-  View* contents_;
-  View* contents_viewport_;
-
-  // The current header and its viewport. |header_| is contained in
-  // |header_viewport_|.
-  View* header_;
-  View* header_viewport_;
-
-  // Horizontal scrollbar.
-  ScrollBar* horiz_sb_;
-
-  // Vertical scrollbar.
-  ScrollBar* vert_sb_;
-
-  // Corner view.
-  View* corner_view_;
-
-  // The min and max height for the bounded scroll view. These are negative
-  // values if the view is not bounded.
-  int min_height_;
-  int max_height_;
-
-  // The background color given to the viewport (for overscroll), and to the
-  // contents when scrolling with layers.
-  SkColor background_color_;
-
-  // If true, never show the horizontal scrollbar (even if the contents is wider
-  // than the viewport).
-  bool hide_horizontal_scrollbar_;
-
-  // In Harmony, the indicator is a focus ring. Pre-Harmony, the indicator is a
-  // different border painter.
-  bool draw_focus_indicator_ = false;
-
-  // Only needed for pre-Harmony. Remove when Harmony is default.
-  bool draw_border_ = false;
-
-  // Focus ring, if one is installed.
-  View* focus_ring_ = nullptr;
-
-  DISALLOW_COPY_AND_ASSIGN(ScrollView);
-};
-
-// VariableRowHeightScrollHelper is intended for views that contain rows of
-// varying height. To use a VariableRowHeightScrollHelper create one supplying
-// a Controller and delegate GetPageScrollIncrement and GetLineScrollIncrement
-// to the helper. VariableRowHeightScrollHelper calls back to the
-// Controller to determine row boundaries.
-class VariableRowHeightScrollHelper {
- public:
-  // The origin and height of a row.
-  struct RowInfo {
-    RowInfo(int origin, int height) : origin(origin), height(height) {}
-
-    // Origin of the row.
-    int origin;
-
-    // Height of the row.
-    int height;
-  };
-
-  // Used to determine row boundaries.
-  class Controller {
-   public:
-    // Returns the origin and size of the row at the specified location.
-    virtual VariableRowHeightScrollHelper::RowInfo GetRowInfo(int y) = 0;
-  };
-
-  // Creates a new VariableRowHeightScrollHelper. Controller is
-  // NOT deleted by this VariableRowHeightScrollHelper.
-  explicit VariableRowHeightScrollHelper(Controller* controller);
-  virtual ~VariableRowHeightScrollHelper();
-
-  // Delegate the View methods of the same name to these. The scroll amount is
-  // determined by querying the Controller for the appropriate row to scroll
-  // to.
-  int GetPageScrollIncrement(ScrollView* scroll_view,
-                             bool is_horizontal, bool is_positive);
-  int GetLineScrollIncrement(ScrollView* scroll_view,
-                             bool is_horizontal, bool is_positive);
-
- protected:
-  // Returns the row information for the row at the specified location. This
-  // calls through to the method of the same name on the controller.
-  virtual RowInfo GetRowInfo(int y);
-
- private:
-  Controller* controller_;
-
-  DISALLOW_COPY_AND_ASSIGN(VariableRowHeightScrollHelper);
-};
-
-// FixedRowHeightScrollHelper is intended for views that contain fixed height
-// height rows. To use a FixedRowHeightScrollHelper delegate
-// GetPageScrollIncrement and GetLineScrollIncrement to it.
-class FixedRowHeightScrollHelper : public VariableRowHeightScrollHelper {
- public:
-  // Creates a FixedRowHeightScrollHelper. top_margin gives the distance from
-  // the top of the view to the first row, and may be 0. row_height gives the
-  // height of each row.
-  FixedRowHeightScrollHelper(int top_margin, int row_height);
-
- protected:
-  // Calculates the bounds of the row from the top margin and row height.
-  RowInfo GetRowInfo(int y) override;
-
- private:
-  int top_margin_;
-  int row_height_;
-
-  DISALLOW_COPY_AND_ASSIGN(FixedRowHeightScrollHelper);
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_CONTROLS_SCROLL_VIEW_H_
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_VIEWS_CONTROLS_SCROLL_VIEW_H_
+#define UI_VIEWS_CONTROLS_SCROLL_VIEW_H_
+
+#include <string>
+
+#include "base/compiler_specific.h"
+#include "base/gtest_prod_util.h"
+#include "base/macros.h"
+#include "ui/views/controls/scrollbar/scroll_bar.h"
+
+namespace gfx {
+class ScrollOffset;
+}
+
+namespace views {
+class ViewObserverTest;
+
+namespace test {
+class ScrollViewTestApi;
+}
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// ScrollView class
+//
+// A ScrollView is used to make any View scrollable. The view is added to
+// a viewport which takes care of clipping.
+//
+// In this current implementation both horizontal and vertical scrollbars are
+// added as needed.
+//
+// The scrollview supports keyboard UI and mousewheel.
+//
+/////////////////////////////////////////////////////////////////////////////
+
+class VIEWS_EXPORT ScrollView : public View, public ScrollBarController {
+ public:
+  static const char kViewClassName[];
+
+  ScrollView();
+
+  ~ScrollView() override;
+
+  // Creates a ScrollView with a theme specific border.
+  static ScrollView* CreateScrollViewWithBorder();
+
+  // Returns the ScrollView for which |contents| is its contents, or null if
+  // |contents| is not in a ScrollView.
+  static ScrollView* GetScrollViewForContents(View* contents);
+
+  // Set the contents. Any previous contents will be deleted. The contents
+  // is the view that needs to scroll.
+  void SetContents(View* a_view);
+  const View* contents() const { return contents_; }
+  View* contents() { return contents_; }
+
+  // Sets the header, deleting the previous header.
+  void SetHeader(View* header);
+
+  // Sets the background color. The default is white when scrolling with layers,
+  // otherwise transparent. An opaque color when scrolling with layers ensures
+  // fonts can be drawn with subpixel antialiasing.
+  void SetBackgroundColor(SkColor color);
+
+  // Returns the visible region of the content View.
+  gfx::Rect GetVisibleRect() const;
+
+  void set_hide_horizontal_scrollbar(bool visible) {
+    hide_horizontal_scrollbar_ = visible;
+  }
+
+  // Turns this scroll view into a bounded scroll view, with a fixed height.
+  // By default, a ScrollView will stretch to fill its outer container.
+  void ClipHeightTo(int min_height, int max_height);
+
+  // Returns whether or not the ScrollView is bounded (as set by ClipHeightTo).
+  bool is_bounded() const { return max_height_ >= 0 && min_height_ >= 0; }
+
+  // Retrieves the width/height reserved for scrollbars. These return 0 if the
+  // scrollbar has not yet been created or in the case of overlay scrollbars.
+  int GetScrollBarLayoutWidth() const;
+  int GetScrollBarLayoutHeight() const;
+
+  // Returns the horizontal/vertical scrollbar. This may return NULL.
+  const ScrollBar* horizontal_scroll_bar() const { return horiz_sb_; }
+  const ScrollBar* vertical_scroll_bar() const { return vert_sb_; }
+
+  // Customize the scrollbar design. ScrollView takes the ownership of the
+  // specified ScrollBar. |horiz_sb| and |vert_sb| cannot be NULL.
+  void SetHorizontalScrollBar(ScrollBar* horiz_sb);
+  void SetVerticalScrollBar(ScrollBar* vert_sb);
+
+  // Sets whether this ScrollView has a focus indicator or not.
+  void SetHasFocusIndicator(bool has_focus_indicator);
+
+  // View overrides:
+  gfx::Size GetPreferredSize() const override;
+  int GetHeightForWidth(int width) const override;
+  void Layout() override;
+  bool OnKeyPressed(const ui::KeyEvent& event) override;
+  bool OnMouseWheel(const ui::MouseWheelEvent& e) override;
+  void OnScrollEvent(ui::ScrollEvent* event) override;
+  void OnGestureEvent(ui::GestureEvent* event) override;
+  const char* GetClassName() const override;
+  void OnNativeThemeChanged(const ui::NativeTheme* theme) override;
+  void ViewHierarchyChanged(
+      const ViewHierarchyChangedDetails& details) override;
+  void OnChildLayerChanged(View* child) override;
+
+  // ScrollBarController overrides:
+  void ScrollToPosition(ScrollBar* source, int position) override;
+  int GetScrollIncrement(ScrollBar* source,
+                         bool is_page,
+                         bool is_positive) override;
+
+  // TODO(djacobo): Remove this method when http://crbug.com/656198  is closed.
+  // Force |contents_viewport_| to enable a Layer().
+  void EnableViewPortLayer();
+
+ private:
+  friend class test::ScrollViewTestApi;
+  FRIEND_TEST_ALL_PREFIXES(ViewObserverTest, ScrollViewChildAddLayerTest);
+
+  class Viewport;
+
+  // Used internally by SetHeader() and SetContents() to reset the view.  Sets
+  // |member| to |new_view|. If |new_view| is non-null it is added to |parent|.
+  void SetHeaderOrContents(View* parent, View* new_view, View** member);
+
+  // Scrolls the minimum amount necessary to make the specified rectangle
+  // visible, in the coordinates of the contents view. The specified rectangle
+  // is constrained by the bounds of the contents view. This has no effect if
+  // the contents have not been set.
+  void ScrollContentsRegionToBeVisible(const gfx::Rect& rect);
+
+  // Computes the visibility of both scrollbars, taking in account the view port
+  // and content sizes.
+  void ComputeScrollBarsVisibility(const gfx::Size& viewport_size,
+                                   const gfx::Size& content_size,
+                                   bool* horiz_is_shown,
+                                   bool* vert_is_shown) const;
+
+  // Shows or hides the scrollbar/corner_view based on the value of
+  // |should_show|.
+  void SetControlVisibility(View* control, bool should_show);
+
+  // Update the scrollbars positions given viewport and content sizes.
+  void UpdateScrollBarPositions();
+
+  // Helpers to get and set the current scroll offset (either from the ui::Layer
+  // or from the |contents_| origin offset).
+  gfx::ScrollOffset CurrentOffset() const;
+  void ScrollToOffset(const gfx::ScrollOffset& offset);
+
+  // Whether the ScrollView scrolls using ui::Layer APIs.
+  bool ScrollsWithLayers() const;
+
+  // Callback entrypoint when hosted Layers are scrolled by the Compositor.
+  void OnLayerScrolled(const gfx::ScrollOffset& offset);
+
+  // Horizontally scrolls the header (if any) to match the contents.
+  void ScrollHeader();
+
+  void AddBorder();
+  void UpdateBorder();
+
+  // Enables view port layering if |child| or any of its descendants has a
+  // layer. Returns true if yes. We short circuit the recursion if we enabled
+  // layering.
+  bool EnableLayeringRecursivelyForChild(View* child);
+
+  // The current contents and its viewport. |contents_| is contained in
+  // |contents_viewport_|.
+  View* contents_;
+  View* contents_viewport_;
+
+  // The current header and its viewport. |header_| is contained in
+  // |header_viewport_|.
+  View* header_;
+  View* header_viewport_;
+
+  // Horizontal scrollbar.
+  ScrollBar* horiz_sb_;
+
+  // Vertical scrollbar.
+  ScrollBar* vert_sb_;
+
+  // Corner view.
+  View* corner_view_;
+
+  // The min and max height for the bounded scroll view. These are negative
+  // values if the view is not bounded.
+  int min_height_;
+  int max_height_;
+
+  // The background color given to the viewport (for overscroll), and to the
+  // contents when scrolling with layers.
+  SkColor background_color_;
+
+  // If true, never show the horizontal scrollbar (even if the contents is wider
+  // than the viewport).
+  bool hide_horizontal_scrollbar_;
+
+  // In Harmony, the indicator is a focus ring. Pre-Harmony, the indicator is a
+  // different border painter.
+  bool draw_focus_indicator_ = false;
+
+  // Only needed for pre-Harmony. Remove when Harmony is default.
+  bool draw_border_ = false;
+
+  // Focus ring, if one is installed.
+  View* focus_ring_ = nullptr;
+
+  // Set to true if we enabled layering for the viewport.
+  bool viewport_layer_enabled_ = false;
+
+  // Set to true if the scroll with layers feature is enabled.
+  const bool scroll_with_layers_enabled_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScrollView);
+};
+
+// VariableRowHeightScrollHelper is intended for views that contain rows of
+// varying height. To use a VariableRowHeightScrollHelper create one supplying
+// a Controller and delegate GetPageScrollIncrement and GetLineScrollIncrement
+// to the helper. VariableRowHeightScrollHelper calls back to the
+// Controller to determine row boundaries.
+class VariableRowHeightScrollHelper {
+ public:
+  // The origin and height of a row.
+  struct RowInfo {
+    RowInfo(int origin, int height) : origin(origin), height(height) {}
+
+    // Origin of the row.
+    int origin;
+
+    // Height of the row.
+    int height;
+  };
+
+  // Used to determine row boundaries.
+  class Controller {
+   public:
+    // Returns the origin and size of the row at the specified location.
+    virtual VariableRowHeightScrollHelper::RowInfo GetRowInfo(int y) = 0;
+  };
+
+  // Creates a new VariableRowHeightScrollHelper. Controller is
+  // NOT deleted by this VariableRowHeightScrollHelper.
+  explicit VariableRowHeightScrollHelper(Controller* controller);
+  virtual ~VariableRowHeightScrollHelper();
+
+  // Delegate the View methods of the same name to these. The scroll amount is
+  // determined by querying the Controller for the appropriate row to scroll
+  // to.
+  int GetPageScrollIncrement(ScrollView* scroll_view,
+                             bool is_horizontal, bool is_positive);
+  int GetLineScrollIncrement(ScrollView* scroll_view,
+                             bool is_horizontal, bool is_positive);
+
+ protected:
+  // Returns the row information for the row at the specified location. This
+  // calls through to the method of the same name on the controller.
+  virtual RowInfo GetRowInfo(int y);
+
+ private:
+  Controller* controller_;
+
+  DISALLOW_COPY_AND_ASSIGN(VariableRowHeightScrollHelper);
+};
+
+// FixedRowHeightScrollHelper is intended for views that contain fixed height
+// height rows. To use a FixedRowHeightScrollHelper delegate
+// GetPageScrollIncrement and GetLineScrollIncrement to it.
+class FixedRowHeightScrollHelper : public VariableRowHeightScrollHelper {
+ public:
+  // Creates a FixedRowHeightScrollHelper. top_margin gives the distance from
+  // the top of the view to the first row, and may be 0. row_height gives the
+  // height of each row.
+  FixedRowHeightScrollHelper(int top_margin, int row_height);
+
+ protected:
+  // Calculates the bounds of the row from the top margin and row height.
+  RowInfo GetRowInfo(int y) override;
+
+ private:
+  int top_margin_;
+  int row_height_;
+
+  DISALLOW_COPY_AND_ASSIGN(FixedRowHeightScrollHelper);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_CONTROLS_SCROLL_VIEW_H_