Implement about:tracing UI for the sampling profiler (Chromium part)

content/browser/tracing/trace_message_filter.h

Index: content/browser/tracing/trace_message_filter.h
diff --git a/content/browser/tracing/trace_message_filter.h b/content/browser/tracing/trace_message_filter.h
index 8da34534604a95a7a28cf6589151d9fc2a8e293e..b36889fd8ded067aae7422db765c3ddbad8a25c1 100644
--- a/content/browser/tracing/trace_message_filter.h
+++ b/content/browser/tracing/trace_message_filter.h
@@ -31,6 +31,9 @@ class TraceMessageFilter : public BrowserMessageFilter {
   void SendBeginTracing(const std::string& category_filter_str,
                         base::debug::TraceLog::Options options);
   void SendEndTracing();
+  void SendBeginContinuousSamplingTracing();
+  void SendEndContinuousSamplingTracing();
+  void SendShowContinuousSamplingTracing();
   void SendGetTraceBufferPercentFull();
   void SendSetWatchEvent(const std::string& category_name,
                          const std::string& event_name);
@@ -43,15 +46,19 @@ class TraceMessageFilter : public BrowserMessageFilter {
   // Message handlers.
   void OnChildSupportsTracing();
   void OnEndTracingAck(const std::vector<std::string>& known_categories);
+  void OnShowContinuousSamplingTracingAck();
   void OnTraceNotification(int notification);
   void OnTraceBufferPercentFullReply(float percent_full);
   void OnTraceDataCollected(const std::string& data);
+  void OnContinuousSamplingTraceDataCollected(const std::string& data);
 
   // ChildTraceMessageFilter exists:
   bool has_child_;
 
   // Awaiting ack for previously sent SendEndTracing
   bool is_awaiting_end_ack_;
+  // Awaiting ack for previously sent SendShowContinuousSamplingTracing
+  bool is_awaiting_continuous_sampling_ack_;
   // Awaiting ack for previously sent SendGetTraceBufferPercentFull
   bool is_awaiting_buffer_percent_full_ack_;