implement SetWatchEvent and WaitForEvent for trace-based-tests

content/browser/trace_controller_impl.h

Index: content/browser/trace_controller_impl.h
diff --git a/content/browser/trace_controller_impl.h b/content/browser/trace_controller_impl.h
index 3564bb3282bfb02297a6234b01c2381a7354ac6d..fbf57dc770e9913d88d20c624d3ff57c5983e1cb 100644
--- a/content/browser/trace_controller_impl.h
+++ b/content/browser/trace_controller_impl.h
@@ -47,6 +47,11 @@ class TraceControllerImpl : public TraceController {
   virtual  bool EndTracingAsync(TraceSubscriber* subscriber) OVERRIDE;
   virtual bool GetTraceBufferPercentFullAsync(
       TraceSubscriber* subscriber) OVERRIDE;
+  bool SetWatchEvent(TraceSubscriber* subscriber,
+                     const char* category_name,
+                     const char* event_name,
+                     int num_occurrences);
+  bool CancelWatchEvent(TraceSubscriber* subscriber);
   virtual void CancelSubscriber(TraceSubscriber* subscriber) OVERRIDE;
 
  private:
@@ -86,7 +91,7 @@ class TraceControllerImpl : public TraceController {
   void OnEndTracingAck(const std::vector<std::string>& known_categories);
   void OnTraceDataCollected(
       const scoped_refptr<base::RefCountedString>& events_str_ptr);
-  void OnTraceBufferFull();
+  void OnTraceNotification(int notification);
   void OnTraceBufferPercentFullReply(float percent_full);
 
   FilterMap filters_;
@@ -101,6 +106,9 @@ class TraceControllerImpl : public TraceController {
   std::set<std::string> known_categories_;
   std::vector<std::string> included_categories_;
   std::vector<std::string> excluded_categories_;
+  int watch_num_occurrences_;
+  std::string watch_category_;
+  std::string watch_name_;
 
   DISALLOW_COPY_AND_ASSIGN(TraceControllerImpl);
 };