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

content/browser/tracing/trace_message_filter.cc

Index: content/browser/tracing/trace_message_filter.cc
diff --git a/content/browser/tracing/trace_message_filter.cc b/content/browser/tracing/trace_message_filter.cc
index e75d786142d90307958bba370a3456efc0f52e66..e250ef16c12a744aff04d6449137f892e2487f68 100644
--- a/content/browser/tracing/trace_message_filter.cc
+++ b/content/browser/tracing/trace_message_filter.cc
@@ -12,6 +12,7 @@ namespace content {
 TraceMessageFilter::TraceMessageFilter() :
     has_child_(false),
     is_awaiting_end_ack_(false),
+    is_awaiting_continuous_sampling_ack_(false),
     is_awaiting_buffer_percent_full_ack_(false) {
 }
 
@@ -28,6 +29,9 @@ void TraceMessageFilter::OnChannelClosing() {
     if (is_awaiting_end_ack_)
       OnEndTracingAck(std::vector<std::string>());
 
+    if (is_awaiting_continuous_sampling_ack_)
+      OnShowContinuousSamplingTracingAck();
+
     if (is_awaiting_buffer_percent_full_ack_)
       OnTraceBufferPercentFullReply(0.0f);
 
@@ -43,8 +47,12 @@ bool TraceMessageFilter::OnMessageReceived(const IPC::Message& message,
     IPC_MESSAGE_HANDLER(TracingHostMsg_ChildSupportsTracing,
                         OnChildSupportsTracing)
     IPC_MESSAGE_HANDLER(TracingHostMsg_EndTracingAck, OnEndTracingAck)
+    IPC_MESSAGE_HANDLER(TracingHostMsg_ShowContinuousSamplingTracingAck,
+                        OnShowContinuousSamplingTracingAck)
     IPC_MESSAGE_HANDLER(TracingHostMsg_TraceDataCollected,
                         OnTraceDataCollected)
+    IPC_MESSAGE_HANDLER(TracingHostMsg_ContinuousSamplingTraceDataCollected,
+                        OnContinuousSamplingTraceDataCollected)
     IPC_MESSAGE_HANDLER(TracingHostMsg_TraceNotification,
                         OnTraceNotification)
     IPC_MESSAGE_HANDLER(TracingHostMsg_TraceBufferPercentFullReply,
@@ -70,6 +78,24 @@ void TraceMessageFilter::SendEndTracing() {
   Send(new TracingMsg_EndTracing);
 }
 
+void TraceMessageFilter::SendBeginContinuousSamplingTracing() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  Send(new TracingMsg_BeginContinuousSamplingTracing(
+      base::TimeTicks::NowFromSystemTraceTime()));
+}
+
+void TraceMessageFilter::SendEndContinuousSamplingTracing() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  Send(new TracingMsg_EndContinuousSamplingTracing);
+}
+
+void TraceMessageFilter::SendShowContinuousSamplingTracing() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(!is_awaiting_continuous_sampling_ack_);
+  is_awaiting_continuous_sampling_ack_ = true;
+  Send(new TracingMsg_ShowContinuousSamplingTracing);
+}
+
 void TraceMessageFilter::SendGetTraceBufferPercentFull() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!is_awaiting_buffer_percent_full_ack_);
@@ -105,12 +131,31 @@ void TraceMessageFilter::OnEndTracingAck(
   }
 }
 
+void TraceMessageFilter::OnShowContinuousSamplingTracingAck() {
+  // is_awaiting_continuous_sampling_ack_ should always be true here,
+  // but check in case the child process is compromised.
+  if (is_awaiting_continuous_sampling_ack_) {
+    is_awaiting_continuous_sampling_ack_ = false;
+    TraceControllerImpl::GetInstance()->OnShowContinuousSamplingTracingAck();
+  } else {
+    NOTREACHED();
+  }
+}
+
 void TraceMessageFilter::OnTraceDataCollected(const std::string& data) {
   scoped_refptr<base::RefCountedString> data_ptr(new base::RefCountedString());
   data_ptr->data() = data;
   TraceControllerImpl::GetInstance()->OnTraceDataCollected(data_ptr);
 }
 
+void TraceMessageFilter::OnContinuousSamplingTraceDataCollected(
+    const std::string& data) {
+  scoped_refptr<base::RefCountedString> data_ptr(new base::RefCountedString());
+  data_ptr->data() = data;
+  TraceControllerImpl::GetInstance()->
+      OnContinuousSamplingTraceDataCollected(data_ptr);
+}
+
 void TraceMessageFilter::OnTraceNotification(int notification) {
   TraceControllerImpl::GetInstance()->OnTraceNotification(notification);
 }