PPAPI: Disallow blocking callbacks while handling a blocking message

mojo/examples/pepper_container_app/mojo_ppapi_globals.cc

 // Copyright 2014 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 "mojo/examples/pepper_container_app/mojo_ppapi_globals.h"
 
 #include "base/logging.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/time/time.h"
 #include "mojo/examples/pepper_container_app/plugin_instance.h"
@@ skipping 26 matching lines @@
                            const base::Closure& closure,
                            int64 delay_ms) OVERRIDE {
     main_thread_message_loop_->PostDelayedTask(
         from_here, closure, base::TimeDelta::FromMilliseconds(delay_ms));
   }
 
   virtual base::MessageLoopProxy* GetMessageLoopProxy() OVERRIDE {
     return main_thread_message_loop_.get();
   }
 
+  virtual bool CurrentlyHandlingBlockingMessage() OVERRIDE {
+    return false;
+  }
+
   // ppapi::thunk::PPB_MessageLoop_API implementation.
   virtual int32_t AttachToCurrentThread() OVERRIDE {
     NOTIMPLEMENTED();
     return PP_ERROR_FAILED;
   }
 
   virtual int32_t Run() OVERRIDE {
     NOTIMPLEMENTED();
     return PP_ERROR_FAILED;
   }
@@ skipping 118 matching lines @@
   NOTIMPLEMENTED();
   return std::string();
 }
 
 void MojoPpapiGlobals::PreCacheFontForFlash(const void* logfontw) {
   NOTIMPLEMENTED();
 }
 
 }  // namespace examples
 }  // namespace mojo