[DevTools] Tracing handler keeps running even after devtools frontend has been closed.

This is happening as the tracing handler is not listening to the frontend close events.
When the front-end is closed, the tracing handler is unaware of it and it keeps collecting the data.
With the active frontend close, the tracing handler should invoke DisableRecording to stop processing further.

Review URL: https://codereview.chromium.org/337213005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278681 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/devtools/devtools_tracing_handler.cc

@@ -200,12 +200,21 @@ void DevToolsTracingHandler::OnBufferUsage(float usage) {
 scoped_refptr<DevToolsProtocol::Response>
 DevToolsTracingHandler::OnEnd(
     scoped_refptr<DevToolsProtocol::Command> command) {
-  buffer_usage_poll_timer_.reset();
-  TracingController::GetInstance()->DisableRecording(
-      base::FilePath(),
+  DisableRecording(
       base::Bind(&DevToolsTracingHandler::BeginReadingRecordingResult,
                  weak_factory_.GetWeakPtr()));
   return command->SuccessResponse(NULL);
 }
 
+void DevToolsTracingHandler::DisableRecording(
+    const TracingController::TracingFileResultCallback& callback) {
+  buffer_usage_poll_timer_.reset();
+  TracingController::GetInstance()->DisableRecording(base::FilePath(),
+                                                     callback);
+}
+
+void DevToolsTracingHandler::OnClientDetached() {
+    DisableRecording();
+}
+
 }  // namespace content

content/browser/devtools/devtools_tracing_handler.h

@@ -24,6 +24,8 @@ class DevToolsTracingHandler : public DevToolsProtocol::Handler {
   explicit DevToolsTracingHandler(Target target);
   virtual ~DevToolsTracingHandler();
 
+  void OnClientDetached();
+
  private:
   void BeginReadingRecordingResult(const base::FilePath& path);
   void ReadRecordingResult(const scoped_refptr<base::RefCountedString>& result);
@@ -38,6 +40,10 @@ class DevToolsTracingHandler : public DevToolsProtocol::Handler {
 
   TracingController::Options TraceOptionsFromString(const std::string& options);
 
+  void DisableRecording(
+      const TracingController::TracingFileResultCallback& callback =
+          TracingController::TracingFileResultCallback());
+
   base::WeakPtrFactory<DevToolsTracingHandler> weak_factory_;
   scoped_ptr<base::Timer> buffer_usage_poll_timer_;
   Target target_;

content/browser/devtools/render_view_devtools_agent_host.cc

@@ -261,6 +261,7 @@ void RenderViewDevToolsAgentHost::OnClientDetached() {
   power_save_blocker_.reset();
 #endif
   overrides_handler_->OnClientDetached();
+  tracing_handler_->OnClientDetached();
   ClientDetachedFromRenderer();
 }