android_webview: Let AwContents manage TouchHandleDrawable

content/public/browser/web_contents_observer.h

Index: content/public/browser/web_contents_observer.h
diff --git a/content/public/browser/web_contents_observer.h b/content/public/browser/web_contents_observer.h
index b72cef60d529b665f8c4099edc125b951bad3e9c..7d64d60c8c36eabc74bba048e343484f001438e8 100644
--- a/content/public/browser/web_contents_observer.h
+++ b/content/public/browser/web_contents_observer.h
@@ -23,6 +23,10 @@
 #include "ui/base/page_transition_types.h"
 #include "ui/base/window_open_disposition.h"
 
+namespace ui {
+class TouchHandleDrawable;
+}
+
 namespace content {
 
 class NavigationEntry;
@@ -453,6 +457,8 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener,
   // Invoked when theme color is changed to |theme_color|.
   virtual void DidChangeThemeColor(SkColor theme_color) {}
 
+  virtual void DidCreateTouchHandle(ui::TouchHandleDrawable* drawable) {}
+
   // Invoked when media is playing or paused.  |id| is unique per player and per
   // RenderFrameHost.  There may be multiple players within a RenderFrameHost
   // and subsequently within a WebContents.  MediaStartedPlaying() will always