[PPAPI] Add browser tests for compositor API

ppapi/proxy/compositor_resource.h

Index: ppapi/proxy/compositor_resource.h
diff --git a/ppapi/proxy/compositor_resource.h b/ppapi/proxy/compositor_resource.h
index f3d13d4ffc71ab522051f80a97538c4599738011..889c101b120b4e12fea84bfd4bc1448705ed7039 100644
--- a/ppapi/proxy/compositor_resource.h
+++ b/ppapi/proxy/compositor_resource.h
@@ -10,6 +10,7 @@
 #include "ppapi/proxy/compositor_layer_resource.h"
 #include "ppapi/proxy/plugin_resource.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
+#include "ppapi/shared_impl/proxy_lock.h"
 #include "ppapi/thunk/ppb_compositor_api.h"
 
 namespace ppapi {
@@ -22,13 +23,9 @@ class PPAPI_PROXY_EXPORT CompositorResource
   CompositorResource(Connection connection,
                      PP_Instance instance);
 
-  bool IsInProgress() const {
-    return TrackedCallback::IsPending(commit_callback_);
-  }
+  bool IsInProgress() const;
 
-  int32_t GenerateResourceId() const {
-    return ++last_resource_id_;
-  }
+  int32_t GenerateResourceId() const;
 
  private:
   virtual ~CompositorResource();
@@ -37,6 +34,7 @@ class PPAPI_PROXY_EXPORT CompositorResource
   virtual thunk::PPB_Compositor_API* AsPPB_Compositor_API() OVERRIDE;
 
   // PluginResource overrides:
+  virtual void NotifyLastPluginRefWasDeleted() OVERRIDE;
   virtual void OnReplyReceived(const ResourceMessageReplyParams& params,
                                const IPC::Message& msg) OVERRIDE;