Internalize JSON chunk management to trace_event.h API.

chrome/browser/ui/webui/tracing_ui.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/tracing_ui.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 45 matching lines @@
   // WebUIMessageHandler implementation.
   virtual WebUIMessageHandler* Attach(WebUI* web_ui);
   virtual void RegisterMessages();
 
   // SelectFileDialog::Listener implementation
   virtual void FileSelected(const FilePath& path, int index, void* params);
   virtual void FileSelectionCanceled(void* params);
 
   // TraceSubscriber implementation.
   virtual void OnEndTracingComplete();
-  virtual void OnTraceDataCollected(const std::string& json_events);
+  virtual void OnTraceDataCollected(const std::string& trace_fragment);
   virtual void OnTraceBufferPercentFullReply(float percent_full);
 
   // Messages.
   void OnTracingControllerInitialized(const ListValue* list);
   void OnBeginTracing(const ListValue* list);
   void OnEndTracingAsync(const ListValue* list);
   void OnBeginRequestBufferPercentFull(const ListValue* list);
   void OnLoadTraceFile(const ListValue* list);
   void OnSaveTraceFile(const ListValue* list);
 
@@ skipping 335 matching lines @@
   }
 }
 
 void TracingMessageHandler::OnEndTracingComplete() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   trace_enabled_ = false;
   web_ui_->CallJavascriptFunction("tracingController.onEndTracingComplete");
 }
 
 void TracingMessageHandler::OnTraceDataCollected(
-    const std::string& json_events) {
+    const std::string& trace_fragment) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  std::string javascript = "tracingController.onTraceDataCollected("
-      + json_events + ");";
+
+  base::debug::TraceResultBuffer::SimpleOutput output;
+  base::debug::TraceResultBuffer trace_buffer;
+  trace_buffer.SetOutputCallback(output.GetCallback());
+  output.Append("tracingController.onTraceDataCollected(");
+  trace_buffer.Start();
+  trace_buffer.AddFragment(trace_fragment);
+  trace_buffer.Finish();
+  output.Append(");");
 
   web_ui_->tab_contents()->render_view_host()->
-      ExecuteJavascriptInWebFrame(string16(), UTF8ToUTF16(javascript));
+      ExecuteJavascriptInWebFrame(string16(), UTF8ToUTF16(output.json_output));
 }
 
 void TracingMessageHandler::OnTraceBufferPercentFullReply(float percent_full) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   web_ui_->CallJavascriptFunction(
       "tracingController.onRequestBufferPercentFullComplete",
       *scoped_ptr<Value>(Value::CreateDoubleValue(percent_full)));
 }
 
 }  // namespace
 
 
 ////////////////////////////////////////////////////////////////////////////////
 //
 // TracingUI
 //
 ////////////////////////////////////////////////////////////////////////////////
 
 TracingUI::TracingUI(TabContents* contents) : ChromeWebUI(contents) {
   AddMessageHandler((new TracingMessageHandler())->Attach(this));
 
   // Set up the chrome://tracing/ source.
   Profile::FromBrowserContext(contents->browser_context())->
       GetChromeURLDataManager()->AddDataSource(CreateTracingHTMLSource());
 }