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

content/browser/tracing/trace_controller_impl.h

Index: content/browser/tracing/trace_controller_impl.h
diff --git a/content/browser/tracing/trace_controller_impl.h b/content/browser/tracing/trace_controller_impl.h
index f24d283a125972a2b5be848f418a972a929e0d7b..08afa52b2d6ff1608bee44bf350e144c40640824 100644
--- a/content/browser/tracing/trace_controller_impl.h
+++ b/content/browser/tracing/trace_controller_impl.h
@@ -30,7 +30,13 @@ class TraceControllerImpl : public TraceController {
   virtual bool BeginTracing(TraceSubscriber* subscriber,
                             const std::string& category_patterns,
                             base::debug::TraceLog::Options options) OVERRIDE;
-  virtual  bool EndTracingAsync(TraceSubscriber* subscriber) OVERRIDE;
+  virtual bool EndTracingAsync(TraceSubscriber* subscriber) OVERRIDE;
+  virtual bool BeginContinuousSamplingTracing(
+      TraceSubscriber* subscriber) OVERRIDE;
+  virtual bool EndContinuousSamplingTracing(
+      TraceSubscriber* subscriber) OVERRIDE;
+  virtual bool ShowContinuousSamplingTracingAsync(
+      TraceSubscriber* subscriber) OVERRIDE;
   virtual bool GetTraceBufferPercentFullAsync(
       TraceSubscriber* subscriber) OVERRIDE;
   virtual bool SetWatchEvent(TraceSubscriber* subscriber,
@@ -50,14 +56,38 @@ class TraceControllerImpl : public TraceController {
   TraceControllerImpl();
   virtual ~TraceControllerImpl();
 
-  bool is_tracing_enabled() const {
-    return can_end_tracing();
+  bool can_begin_tracing(TraceSubscriber* subscriber) const {
+    return !is_tracing_ &&
+        (subscriber_ == NULL || subscriber == subscriber_);
+  }
+
+  bool can_end_tracing(TraceSubscriber* subscriber) const {
+    return is_tracing_ && pending_end_ack_count_ == 0 &&
+      subscriber == subscriber_;
   }
 
-  bool can_end_tracing() const {
+  bool is_tracing_enabled() const {
     return is_tracing_ && pending_end_ack_count_ == 0;
   }
 
+  bool can_begin_continuous_sampling_tracing(
+      TraceSubscriber* subscriber) const {
+    return !is_continuous_sampling_tracing_ &&
+        (continuous_sampling_subscriber_ == NULL ||
+         subscriber == continuous_sampling_subscriber_);
+  }
+
+  bool can_end_continuous_sampling_tracing(TraceSubscriber* subscriber) const {
+    return is_continuous_sampling_tracing_ &&
+        pending_show_continuous_sampling_ack_count_ == 0 &&
+        subscriber == continuous_sampling_subscriber_;
+  }
+
+  bool is_continuous_sampling_tracing_enabled() const {
+    return is_continuous_sampling_tracing_ &&
+        pending_show_continuous_sampling_ack_count_ == 0;
+  }
+
   // Can get Buffer Percent Full
   bool can_get_buffer_percent_full() const {
     return is_tracing_ &&
@@ -65,30 +95,32 @@ class TraceControllerImpl : public TraceController {
         pending_bpf_ack_count_ == 0;
   }
 
-  bool can_begin_tracing(TraceSubscriber* subscriber) const {
-    return !is_tracing_ &&
-        (subscriber_ == NULL || subscriber == subscriber_);
-  }
-
   // Methods for use by TraceMessageFilter.
 
   void AddFilter(TraceMessageFilter* filter);
   void RemoveFilter(TraceMessageFilter* filter);
   void OnTracingBegan(TraceSubscriber* subscriber);
   void OnEndTracingAck(const std::vector<std::string>& known_category_groups);
+  void OnShowContinuousSamplingTracingAck();
   void OnTraceDataCollected(
       const scoped_refptr<base::RefCountedString>& events_str_ptr);
+  void OnContinuousSamplingTraceDataCollected(
+      const scoped_refptr<base::RefCountedString>& events_str_ptr);
   void OnTraceNotification(int notification);
   void OnTraceBufferPercentFullReply(float percent_full);
 
   FilterMap filters_;
   TraceSubscriber* subscriber_;
+  TraceSubscriber* continuous_sampling_subscriber_;
   // Pending acks for EndTracingAsync:
   int pending_end_ack_count_;
+  // Pending acks for ShowContinuousSamplingTracingAsync:
+  int pending_show_continuous_sampling_ack_count_;
   // Pending acks for GetTraceBufferPercentFullAsync:
   int pending_bpf_ack_count_;
   float maximum_bpf_;
   bool is_tracing_;
+  bool is_continuous_sampling_tracing_;
   bool is_get_category_groups_;
   std::set<std::string> known_category_groups_;
   std::string watch_category_;