Adding an api to get number of event listeners.

chrome/test/chromedriver/chrome/web_view_impl.h

Index: chrome/test/chromedriver/chrome/web_view_impl.h
diff --git a/chrome/test/chromedriver/chrome/web_view_impl.h b/chrome/test/chromedriver/chrome/web_view_impl.h
index 6297e064d149e0c6111163c95bd282f9001ebcf9..78dd15a5036af755eae56caa760f4e8a0fb207c8 100644
--- a/chrome/test/chromedriver/chrome/web_view_impl.h
+++ b/chrome/test/chromedriver/chrome/web_view_impl.h
@@ -22,6 +22,7 @@ class Value;
 class DebuggerTracker;
 class DevToolsClient;
 class DomTracker;
+class EventListenerCount;
 class FrameTracker;
 class GeolocationOverrideManager;
 class HeapSnapshotTaker;
@@ -87,6 +88,7 @@ class WebViewImpl : public WebView {
       const base::DictionaryValue& element,
       const std::vector<base::FilePath>& files) OVERRIDE;
   virtual Status TakeHeapSnapshot(scoped_ptr<base::Value>* snapshot) OVERRIDE;
+  virtual Status GetEventListenersCount(int* count) OVERRIDE;
 
  private:
   Status CallAsyncFunctionInternal(const std::string& frame,
@@ -107,6 +109,7 @@ class WebViewImpl : public WebView {
   scoped_ptr<HeapSnapshotTaker> heap_snapshot_taker_;
   scoped_ptr<DebuggerTracker> debugger_;
   scoped_ptr<DevToolsClient> client_;
+  scoped_ptr<EventListenerCount> event_listener_count_;
 };
 
 namespace internal {