reland 121901, PPAPI: Add unlocking for PPP calls and callbacks...

ppapi/proxy/ppb_message_loop_proxy.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 "ppapi/proxy/ppb_message_loop_proxy.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
@@ skipping 37 matching lines @@
     tracked_objects::Location from_here;
     base::Closure closure;
     int64 delay_ms;
   };
 
   // Returns true if the object is associated with the current thread.
   bool IsCurrent() const;
 
   // Handles posting to the message loop if there is one, or the pending queue
   // if there isn't.
+  // NOTE: The given closure will be run *WITHOUT* acquiring the Proxy lock.
+  //       This only makes sense for user code and completely thread-safe
+  //       proxy operations (e.g., MessageLoop::QuitClosure).
   void PostClosure(const tracked_objects::Location& from_here,
                    const base::Closure& closure,
                    int64 delay_ms);
 
   // TLS destructor function.
   static void ReleaseMessageLoop(void* value);
 
   // Created when we attach to the current thread, since MessageLoop assumes
   // that it's created on the thread it will run on.
   scoped_ptr<MessageLoop> loop_;
@@ skipping 122 matching lines @@
     return false;  // Can't be current if there's nothing in the slot.
   return static_cast<const void*>(globals->msg_loop_slot()->Get()) ==
          static_cast<const void*>(this);
 }
 
 void MessageLoopResource::PostClosure(
     const tracked_objects::Location& from_here,
     const base::Closure& closure,
     int64 delay_ms) {
   if (loop_.get()) {
-    loop_->PostDelayedTask(
-        from_here, closure, base::TimeDelta::FromMilliseconds(delay_ms));
+    loop_->PostDelayedTask(from_here,
+                           closure,
+                           base::TimeDelta::FromMilliseconds(delay_ms));
   } else {
     TaskInfo info;
     info.from_here = FROM_HERE;
     info.closure = closure;
     info.delay_ms = delay_ms;
     pending_tasks_.push_back(info);
   }
 }
 
 // static
@@ skipping 74 matching lines @@
 PPB_MessageLoop_Proxy::~PPB_MessageLoop_Proxy() {
 }
 
 // static
 const PPB_MessageLoop_Dev_0_1* PPB_MessageLoop_Proxy::GetInterface() {
   return &ppb_message_loop_interface;
 }
 
 }  // namespace proxy
 }  // namespace ppapi