MacViews: Enable word lookup for selectable views::Labels and multi-line text.

ui/views/controls/label.h

Index: ui/views/controls/label.h
diff --git a/ui/views/controls/label.h b/ui/views/controls/label.h
index 6293cff501081dba7bd287548fcdd42d8bf16161..227929cb2b7d389a65e1b04a19f633edcc9eb7d3 100644
--- a/ui/views/controls/label.h
+++ b/ui/views/controls/label.h
@@ -13,6 +13,7 @@
 #include "ui/views/context_menu_controller.h"
 #include "ui/views/selection_controller_delegate.h"
 #include "ui/views/view.h"
+#include "ui/views/word_lookup_client.h"
 
 namespace views {
 class LabelSelectionTest;
@@ -22,6 +23,7 @@ class SelectionController;
 // A view subclass that can display a string.
 class VIEWS_EXPORT Label : public View,
                            public ContextMenuController,
+                           public WordLookupClient,

[msw, 2017/01/20 16:45:32]

nit: it'd be nice if we could use composition instead of inheritance, but it's
not a blocker.

[karandeepb, 2017/01/23 00:20:25]

That may turn out to be a bit more verbose.

                            public SelectionControllerDelegate,
                            public ui::SimpleMenuModel::Delegate {
  public:
@@ -185,6 +187,7 @@ class VIEWS_EXPORT Label : public View,
   const char* GetClassName() const override;
   View* GetTooltipHandlerForPoint(const gfx::Point& point) override;
   bool CanProcessEventsWithinSubtree() const override;
+  WordLookupClient* GetWordLookupClient() override;
   void GetAccessibleNodeData(ui::AXNodeData* node_data) override;
   bool GetTooltipText(const gfx::Point& p,
                       base::string16* tooltip) const override;
@@ -233,6 +236,11 @@ class VIEWS_EXPORT Label : public View,
                               const gfx::Point& point,
                               ui::MenuSourceType source_type) override;
 
+  // WordLookupClient overrides:
+  bool GetDecoratedWordAtPoint(const gfx::Point& point,
+                               gfx::DecoratedText* decorated_word,
+                               gfx::Point* baseline_point) override;
+
   // SelectionControllerDelegate overrides:
   gfx::RenderText* GetRenderTextForSelectionController() override;
   bool IsReadOnly() const override;