Route 'Select All' OS method through RenderWidgetHostDelegate.

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 8f3c90a7a0dbf817d97e434baab3e5e46049b005..2899cafc177424250f238196113033a3a535ddc1 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -563,10 +563,11 @@ class CONTENT_EXPORT WebContentsImpl
   BrowserAccessibilityManager* GetRootBrowserAccessibilityManager() override;
   BrowserAccessibilityManager* GetOrCreateRootBrowserAccessibilityManager()
       override;
-  // Following three functions are already listed under WebContents overrides.
+  // The following 4 functions are already listed under WebContents overrides:
   // void Cut() override;
   // void Copy() override;
   // void Paste() override;
+  // void SelectAll() override;
   void MoveRangeSelectionExtent(const gfx::Point& extent) override;
   void SelectRange(const gfx::Point& base, const gfx::Point& extent) override;