PPAPI: Make CompletionCallbacks work right on background threads.

ppapi/shared_impl/test_globals.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/shared_impl/test_globals.h"
 
 namespace ppapi {
 
 TestGlobals::TestGlobals()
     : ppapi::PpapiGlobals(),
@@ skipping 51 matching lines @@
                                 const std::string& source,
                                 const std::string& value) {
 }
 
 void TestGlobals::BroadcastLogWithSource(PP_Module module,
                                          PP_LogLevel_Dev level,
                                          const std::string& source,
                                          const std::string& value) {
 }
 
+MessageLoopShared* TestGlobals::GetCurrentMessageLoop() {
+  return NULL;
+}
+
+bool TestGlobals::IsHostGlobals() const {
+  // Pretend to be the host-side, for code that expects one or the other.
+  // TODO(dmichael): just make it settable which one we're pretending to be?
+  return true;
+}
+
 }  // namespace ppapi