Collect profiler stats from browser child processes.

content/browser/profiler_controller_impl.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 "content/browser/profiler_controller_impl.h"
+
+#include "base/values.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/profiler_subscriber.h"
+
+using content::BrowserThread;
+
+ProfilerControllerImpl::ProfilerControllerImpl() : subscriber_(NULL) {
+}
+
+ProfilerControllerImpl::~ProfilerControllerImpl() {
+}
+
+ProfilerControllerImpl* ProfilerControllerImpl::GetInstance() {
+  return Singleton<ProfilerControllerImpl>::get();
+}
+
+content::ProfilerController* content::ProfilerController::GetInstance() {

[jam, 2011/11/28 15:17:34]

by convention, put statics at top of the funcitons. also, content api statics go
first

[ramant (doing other things), 2011/11/29 01:32:20]

Done.

+  return ProfilerControllerImpl::GetInstance();
+}
+
+void ProfilerControllerImpl::Register(ProfilerSubscriber* subscriber) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(!subscriber_);
+  subscriber_ = subscriber;
+}
+
+void ProfilerControllerImpl::Unregister(ProfilerSubscriber* subscriber) {
+  if (subscriber == subscriber_) {
+    subscriber_ = NULL;
+  }
+}
+
+void ProfilerControllerImpl::OnPendingProcesses(int sequence_number,
+                                                int pending_processes) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (subscriber_) {
+    subscriber_->OnPendingProcesses(sequence_number, pending_processes);
+  }
+}
+
+void ProfilerControllerImpl::OnProfilerDataCollected(
+    int sequence_number,
+    const base::DictionaryValue& profiler_data) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (subscriber_) {
+    subscriber_->OnProfilerDataCollected(sequence_number, profiler_data);

[jam, 2011/11/28 15:17:34]

why call the subscriber on the IO thread? the interface should hide internal
thread implementations and make this interface all one thread (i.e.
register/unregister/get notified on the same thread (UI) ). 

it seems that there's a bug (which the above would fix) since a subscriber can
unregister on the UI thread, but as subscriber_ is being nulled in
ProfilerControllerImpl on the UI thread, it can be used on the IO thread.

[ramant (doing other things), 2011/11/29 01:32:20]

Done.

+  }
+}