Implement WebThread::{add,remove}TaskObserver.

Re-landing r113010 with clang style fixes.

R=tony@chromium.org

Review URL: http://codereview.chromium.org/8805027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@113073 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 48 insertions, 0 deletions

diff --git a/webkit/glue/webthread_impl.cc b/webkit/glue/webthread_impl.cc
index 236497e..ac32ccb 100644
--- a/webkit/glue/webthread_impl.cc
+++ b/webkit/glue/webthread_impl.cc
@@ -10,9 +10,48 @@
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/message_loop.h"
+#include "base/threading/platform_thread.h"
 
 namespace webkit_glue {
 
+WebThreadBase::WebThreadBase() { }
+WebThreadBase::~WebThreadBase() { }
+
+class WebThreadBase::TaskObserverAdapter : public MessageLoop::TaskObserver {
+public:
+  TaskObserverAdapter(WebThread::TaskObserver* observer)
+      : observer_(observer) { }
+
+  // WebThread::TaskObserver does not have a willProcessTask method.
+  virtual void WillProcessTask(base::TimeTicks) OVERRIDE { }
+
+  virtual void DidProcessTask(base::TimeTicks) OVERRIDE {
+    observer_->didProcessTask();
+  }
+
+private:
+  WebThread::TaskObserver* observer_;
+};
+
+void WebThreadBase::addTaskObserver(TaskObserver* observer) {
+  CHECK(IsCurrentThread());
+  std::pair<TaskObserverMap::iterator, bool> result = task_observer_map_.insert(
+      std::make_pair(observer, static_cast<TaskObserverAdapter*>(NULL)));
+  if (result.second)
+    result.first->second = new TaskObserverAdapter(observer);
+  MessageLoop::current()->AddTaskObserver(result.first->second);
+}
+
+void WebThreadBase::removeTaskObserver(TaskObserver* observer) {
+  CHECK(IsCurrentThread());
+  TaskObserverMap::iterator iter = task_observer_map_.find(observer);
+  if (iter == task_observer_map_.end())
+    return;
+  MessageLoop::current()->RemoveTaskObserver(iter->second);
+  delete iter->second;
+  task_observer_map_.erase(iter);
+}
+
 WebThreadImpl::WebThreadImpl(const char* name)
     : thread_(new base::Thread(name)) {
   thread_->Start();
@@ -22,6 +61,7 @@ void WebThreadImpl::postTask(Task* task) {
   thread_->message_loop()->PostTask(
       FROM_HERE, base::Bind(&WebKit::WebThread::Task::run, base::Owned(task)));
 }
+
 void WebThreadImpl::postDelayedTask(
     Task* task, long long delay_ms) {
   thread_->message_loop()->PostDelayedTask(
@@ -30,6 +70,10 @@ void WebThreadImpl::postDelayedTask(
       delay_ms);
 }
 
+bool WebThreadImpl::IsCurrentThread() const {
+  return thread_->thread_id() == base::PlatformThread::CurrentId();
+}
+
 WebThreadImpl::~WebThreadImpl() {
   thread_->Stop();
 }
@@ -52,6 +96,10 @@ void WebThreadImplForMessageLoop::postDelayedTask(
       delay_ms);
 }
 
+bool WebThreadImplForMessageLoop::IsCurrentThread() const {
+  return message_loop_->BelongsToCurrentThread();
+}
+
 WebThreadImplForMessageLoop::~WebThreadImplForMessageLoop() {
 }