Make it possible to have 1 PpapiGlobals per thread. Update unit tests.

ppapi/shared_impl/ppapi_globals.h

 // Copyright (c) 2011 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.
 
 #ifndef PPAPI_SHARED_IMPL_PPAPI_GLOBALS_H_
 #define PPAPI_SHARED_IMPL_PPAPI_GLOBALS_H_
 
 #include "base/basictypes.h"
+#include "base/threading/thread_local.h"  // For testing purposes only.
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_module.h"
 #include "ppapi/shared_impl/api_id.h"
 #include "ppapi/shared_impl/ppapi_shared_export.h"
 
 namespace ppapi {
 
 class CallbackTracker;
 class FunctionGroupBase;
 class ResourceTracker;
 class VarTracker;
 
 // Abstract base class
 class PPAPI_SHARED_EXPORT PpapiGlobals {
  public:
   PpapiGlobals();
   virtual ~PpapiGlobals();
 
   // Getter for the global singleton.
-  inline static PpapiGlobals* Get() { return ppapi_globals_; }
+  inline static PpapiGlobals* Get() {
+    if (ppapi_globals_)
+      return ppapi_globals_;
+    return ppapi_globals_for_test_.Get();
+  }
+  static void SetPpapiGlobalsForTest(PpapiGlobals* ptr) {
+    ppapi_globals_for_test_.Set(ptr);
+    ppapi_globals_ = NULL;
+  }
 
   // Retrieves the corresponding tracker.
   virtual ResourceTracker* GetResourceTracker() = 0;
   virtual VarTracker* GetVarTracker() = 0;
   virtual CallbackTracker* GetCallbackTrackerForInstance(
       PP_Instance instance) = 0;
 
   // Returns the function object corresponding to the given ID, or NULL if
   // there isn't one.
   virtual FunctionGroupBase* GetFunctionAPI(PP_Instance inst, ApiID id) = 0;
 
   // Returns the PP_Module associated with the given PP_Instance, or 0 on
   // failure.
   virtual PP_Module GetModuleForInstance(PP_Instance instance) = 0;
 
  private:
   static PpapiGlobals* ppapi_globals_;
+  static base::ThreadLocalPointer<PpapiGlobals> ppapi_globals_for_test_;
 
   DISALLOW_COPY_AND_ASSIGN(PpapiGlobals);
 };
 
 }  // namespace ppapi
 
 #endif  // PPAPI_SHARED_IMPL_PPAPI_GLOBALS_H_