Make some organization in RenderWidgetHost clearer.

content/browser/renderer_host/render_widget_host.h

Index: content/browser/renderer_host/render_widget_host.h
diff --git a/content/browser/renderer_host/render_widget_host.h b/content/browser/renderer_host/render_widget_host.h
index 71db8b7f1bdcc71da31126495d22eb076e829ee4..03d8426e52a1e4237c33b1cb7c1cc555ef6daf17 100644
--- a/content/browser/renderer_host/render_widget_host.h
+++ b/content/browser/renderer_host/render_widget_host.h
@@ -474,27 +474,29 @@ class CONTENT_EXPORT RenderWidgetHost : public IPC::Channel::Listener,
   virtual bool PreHandleKeyboardEvent(const NativeWebKeyboardEvent& event,
                                       bool* is_keyboard_shortcut);
 
-  // Called when a keyboard event was not processed by the renderer. This is
-  // overridden by RenderView to send upwards to its delegate.
+  // "RenderWidgetHostDelegate" ------------------------------------------------
+  // There is no RenderWidgetHostDelegate but the following methods serve the
+  // same purpose. They are overridden by RenderView to send upwards to its
+  // delegate.
+
+  // Called when a keyboard event was not processed by the renderer.
   virtual void UnhandledKeyboardEvent(const NativeWebKeyboardEvent& event) {}
 
-  // Called when a mousewheel event was not processed by the renderer. This is
-  // overridden by RenderView to send upwards to its delegate.
+  // Called when a mousewheel event was not processed by the renderer.
   virtual void UnhandledWheelEvent(const WebKit::WebMouseWheelEvent& event) {}
 
   // Notification that the user has made some kind of input that could
-  // perform an action. The render view host overrides this to forward the
-  // information to its delegate (see corresponding function in
-  // RenderViewHostDelegate). The gestures that count are 1) any mouse down
+  // perform an action. The gestures that count are 1) any mouse down
   // event and 2) enter or space key presses.
   virtual void OnUserGesture() {}
 
   // Callbacks for notification when the renderer becomes unresponsive to user
-  // input events, and subsequently responsive again. RenderViewHost overrides
-  // these to tell its delegate to show the user a warning.
+  // input events, and subsequently responsive again.
   virtual void NotifyRendererUnresponsive() {}
   virtual void NotifyRendererResponsive() {}
 
+  // ---------------------------------------------------------------------------
+
   // RenderViewHost overrides this method to impose further restrictions on when
   // to allow mouse lock.
   // Once the request is approved or rejected, GotResponseToLockMouseRequest()