Store unsaved trace data on exit.

content/browser/browser_main_loop.cc

 // Copyright (c) 2012 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 "content/browser/browser_main_loop.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/file_util.h"
@@ skipping 882 matching lines @@
     URLDataManager::DeleteDataSources();
   }
 #endif  // !defined(OS_IOS)
 
   if (parts_) {
     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:PostDestroyThreads");
     parts_->PostDestroyThreads();
   }
 }
 
+void BrowserMainLoop::StopStartupTracingTimer() {
+  startup_trace_timer_.Stop();
+}
+
 void BrowserMainLoop::InitializeMainThread() {
   TRACE_EVENT0("startup", "BrowserMainLoop::InitializeMainThread");
   const char* kThreadName = "CrBrowserMain";
   base::PlatformThread::SetName(kThreadName);
   if (main_message_loop_)
     main_message_loop_->set_thread_name(kThreadName);
 
   // Register the main thread by instantiating it, but don't call any methods.
   main_thread_.reset(
       new BrowserThreadImpl(BrowserThread::UI, base::MessageLoop::current()));
@@ skipping 184 matching lines @@
   DCHECK(base::MessageLoopForUI::IsCurrent());
   if (parameters_.ui_task)
     base::MessageLoopForUI::current()->PostTask(FROM_HERE,
                                                 *parameters_.ui_task);
 
   base::RunLoop run_loop;
   run_loop.Run();
 #endif
 }
 
-void BrowserMainLoop::InitStartupTracing(const CommandLine& command_line) {
-  DCHECK(is_tracing_startup_);
-
+base::FilePath BrowserMainLoop::GetStartupTraceFileName(
+    const base::CommandLine& command_line) const {

[sky, 2014/06/27 22:27:25]

How come this and GetShutdownProfileFileName can't be the same?

[Alexander Alekseev, 2014/06/30 16:19:40]

They are different in semantics.

Startup trace file can have special value "none".
Empty startup trace file value is handled differently on Android and other
systems.

Shutdown trace file has no special values and defaults to "chrometrace.log" on
all systems.

I can drop both GetStartupTraceFileName / GetShutdownProfileFileName and move
it's code to callers. But it seems that having two different functions is more
readable.

   base::FilePath trace_file = command_line.GetSwitchValuePath(
       switches::kTraceStartupFile);
   // trace_file = "none" means that startup events will show up for the next
   // begin/end tracing (via about:tracing or AutomationProxy::BeginTracing/
   // EndTracing, for example).
   if (trace_file == base::FilePath().AppendASCII("none"))
-    return;
+    return trace_file;
 
   if (trace_file.empty()) {
 #if defined(OS_ANDROID)
     TracingControllerAndroid::GenerateTracingFilePath(&trace_file);
 #else
     // Default to saving the startup trace into the current dir.
     trace_file = base::FilePath().AppendASCII("chrometrace.log");
 #endif
   }
 
+  return trace_file;
+}
+
+void BrowserMainLoop::InitStartupTracing(const CommandLine& command_line) {
+  DCHECK(is_tracing_startup_);
+
+  startup_trace_file_ = GetStartupTraceFileName(parsed_command_line_);
+
   std::string delay_str = command_line.GetSwitchValueASCII(
       switches::kTraceStartupDuration);
   int delay_secs = 5;
   if (!delay_str.empty() && !base::StringToInt(delay_str, &delay_secs)) {
     DLOG(WARNING) << "Could not parse --" << switches::kTraceStartupDuration
         << "=" << delay_str << " defaulting to 5 (secs)";
     delay_secs = 5;
   }
 
-  BrowserThread::PostDelayedTask(
-      BrowserThread::UI, FROM_HERE,
-      base::Bind(&BrowserMainLoop::EndStartupTracing,
-                 base::Unretained(this), trace_file),
-      base::TimeDelta::FromSeconds(delay_secs));
+  startup_trace_timer_.Start(FROM_HERE,
+                             base::TimeDelta::FromSeconds(delay_secs),
+                             this,
+                             &BrowserMainLoop::EndStartupTracing);
 }
 
-void BrowserMainLoop::EndStartupTracing(const base::FilePath& trace_file) {
+void BrowserMainLoop::EndStartupTracing() {
   is_tracing_startup_ = false;
   TracingController::GetInstance()->DisableRecording(
-      trace_file, base::Bind(&OnStoppedStartupTracing));
+      startup_trace_file_, base::Bind(&OnStoppedStartupTracing));
 }
 
 }  // namespace content