Notify WebContentsObservers of user interactions.

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 c2fcffbe0f2efb50491184386b27a6aa11d21753..04030e46b493935b07f451f041d34f641a861e99 100644
--- a/content/public/browser/web_contents_observer.h
+++ b/content/public/browser/web_contents_observer.h
@@ -13,6 +13,7 @@
 #include "content/public/common/security_style.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_sender.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/page_transition_types.h"
 #include "ui/base/window_open_disposition.h"
@@ -313,8 +314,15 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener,
   virtual void NavigationStopped() {}
 
   // This indicates that the next navigation was triggered by a user gesture.
+  // TODO(dominickn): remove this method in favor of DidStartUserInteraction,
+  // with the appropriate filtering by input event type.
   virtual void DidGetUserGesture() {}
 
+  // Called when there has been direct user interaction with the web contents.
+  // Direct user input includes 1) any mouse down event; 2) any mouse wheel
+  // event; 3) any raw key down event; and 4) any gesture tap event.
+  virtual void DidStartUserInteraction(const blink::WebInputEvent::Type type) {}

[nasko, 2015/10/26 17:18:44]

Any method that has a Start in its name should have a corresponding Stop method.
I don't see one. Why is that?

[dominickn, 2015/10/27 07:03:57]

The naming was a reviewer suggestion. I've changed it to remove the Start and
the implication that there should be a stop.

+
   // This method is invoked when a RenderViewHost of this WebContents was
   // configured to ignore UI events, and an UI event took place.
   virtual void DidGetIgnoredUIEvent() {}