RenderTextHarfBuzz: Add support for multi line text selection.

ui/views/controls/label.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_LABEL_H_
 #define UI_VIEWS_CONTROLS_LABEL_H_
 
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
@@ skipping 129 matching lines @@
 
   // Like SizeToFit, but uses a smaller width if possible.
   void SetMaximumWidth(int max_width);
 
   // Sets whether the preferred size is empty when the label is not visible.
   void set_collapse_when_hidden(bool value) { collapse_when_hidden_ = value; }
 
   // Get the text as displayed to the user, respecting the obscured flag.
   base::string16 GetDisplayTextForTesting();
 
+  // Returns true if the label can be made selectable. For example, links do not
+  // support text selection.
+  // Subclasses should override this function in case they want to selectively
+  // support text selection. If a subclass stops supporting text selection, it
+  // should call SetSelectable(false).
+  virtual bool IsSelectionSupported() const;
+
   // Returns true if the label is selectable. Default is false.
   bool selectable() const { return !!selection_controller_; }
 
   // Sets whether the label is selectable. False is returned if the call fails,
   // i.e. when selection is not supported but |selectable| is true. For example,
   // obscured labels do not support text selection.
   bool SetSelectable(bool selectable);
 
   // Returns true if the label has a selection.
   bool HasSelection() const;
@@ skipping 28 matching lines @@
   virtual std::unique_ptr<gfx::RenderText> CreateRenderText(
       const base::string16& text,
       gfx::HorizontalAlignment alignment,
       gfx::DirectionalityMode directionality,
       gfx::ElideBehavior elide_behavior) const;
 
   void PaintText(gfx::Canvas* canvas);
 
   SkColor disabled_color() const { return actual_disabled_color_; }
 
-  // Returns true if the label can be made selectable. For example, links do not
-  // support text selection.
-  // Subclasses should override this function in case they want to selectively
-  // support text selection. If a subclass stops supporting text selection, it
-  // should call SetSelectable(false).
-  virtual bool IsSelectionSupported() const;
-
   // View:
   void OnBoundsChanged(const gfx::Rect& previous_bounds) override;
   void VisibilityChanged(View* starting_from, bool is_visible) override;
   void OnPaint(gfx::Canvas* canvas) override;
   void OnDeviceScaleFactorChanged(float device_scale_factor) override;
   void OnNativeThemeChanged(const ui::NativeTheme* theme) override;
   gfx::NativeCursor GetCursor(const ui::MouseEvent& event) override;
   void OnFocus() override;
   void OnBlur() override;
   bool OnMousePressed(const ui::MouseEvent& event) override;
@@ skipping 128 matching lines @@
   // Context menu related members.
   ui::SimpleMenuModel context_menu_contents_;
   std::unique_ptr<views::MenuRunner> context_menu_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(Label);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_LABEL_H_