Remove BrowserThread-specific implementation of MessageLoopProxy.

content/browser/browser_thread_impl.cc

Index: content/browser/browser_thread_impl.cc
diff --git a/content/browser/browser_thread_impl.cc b/content/browser/browser_thread_impl.cc
index 297bb30d7cbbcc660439f6b19738ae13eea039b1..50108d9105044cdcc37aa2fb9fbe7882fe14d51a 100644
--- a/content/browser/browser_thread_impl.cc
+++ b/content/browser/browser_thread_impl.cc
@@ -175,53 +175,6 @@ bool BrowserThreadImpl::PostTaskHelper(
   return !!message_loop;
 }
 
-// An implementation of MessageLoopProxy to be used in conjunction
-// with BrowserThread.
-class BrowserThreadMessageLoopProxy : public base::MessageLoopProxy {
- public:
-  explicit BrowserThreadMessageLoopProxy(BrowserThread::ID identifier)
-      : id_(identifier) {
-  }
-
-  // MessageLoopProxy implementation.
-  virtual bool PostDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task, int64 delay_ms) OVERRIDE {
-    return BrowserThread::PostDelayedTask(id_, from_here, task, delay_ms);
-  }
-  virtual bool PostDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task, base::TimeDelta delay) OVERRIDE {
-    return BrowserThread::PostDelayedTask(id_, from_here, task, delay);
-  }
-
-  virtual bool PostNonNestableDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task,
-      int64 delay_ms) OVERRIDE {
-    return BrowserThread::PostNonNestableDelayedTask(id_, from_here, task,
-                                                     delay_ms);
-  }
-  virtual bool PostNonNestableDelayedTask(
-      const tracked_objects::Location& from_here,
-      const base::Closure& task,
-      base::TimeDelta delay) OVERRIDE {
-    return BrowserThread::PostNonNestableDelayedTask(id_, from_here, task,
-                                                     delay);
-  }
-
-  virtual bool RunsTasksOnCurrentThread() const OVERRIDE {
-    return BrowserThread::CurrentlyOn(id_);
-  }
-
- protected:
-  virtual ~BrowserThreadMessageLoopProxy() {}
-
- private:
-  BrowserThread::ID id_;
-  DISALLOW_COPY_AND_ASSIGN(BrowserThreadMessageLoopProxy);
-};
-
 // static
 bool BrowserThread::PostBlockingPoolTask(
     const tracked_objects::Location& from_here,
@@ -389,9 +342,30 @@ bool BrowserThread::GetCurrentThreadIdentifier(ID* identifier) {
 // static
 scoped_refptr<base::MessageLoopProxy>
 BrowserThread::GetMessageLoopProxyForThread(ID identifier) {
-  scoped_refptr<base::MessageLoopProxy> proxy(
-      new BrowserThreadMessageLoopProxy(identifier));
-  return proxy;
+  if (g_globals == NULL)
+    return NULL;
+
+  BrowserThread::ID current_thread;
+  bool guaranteed_to_outlive_target_thread =
+      GetCurrentThreadIdentifier(&current_thread) &&
+      current_thread <= identifier;
+
+  BrowserThreadGlobals& globals = g_globals.Get();
+  if (!guaranteed_to_outlive_target_thread)
+    globals.lock.Acquire();
+
+  base::Thread* thread = globals.threads[identifier];
+  if (!thread) {
+    if (!guaranteed_to_outlive_target_thread)
+      globals.lock.Release();
+    return NULL;
+  }
+  scoped_refptr<base::MessageLoopProxy> loop = thread->message_loop_proxy();
+
+  if (!guaranteed_to_outlive_target_thread)
+    globals.lock.Release();
+
+  return loop;
 }
 
 // static