[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..923257c80a04d41f943152b6b207ac6663f2b3f7 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 {
@@ -23,10 +24,17 @@ class PPAPI_PROXY_EXPORT CompositorResource
                      PP_Instance instance);
 
   bool IsInProgress() const {
+    ProxyLock::AssertAcquiredDebugOnly();
     return TrackedCallback::IsPending(commit_callback_);
   }
 
+  bool bound_to_instance() const {
+    ProxyLock::AssertAcquiredDebugOnly();
+    return bound_to_instance_;
+  }
+
   int32_t GenerateResourceId() const {
+    ProxyLock::AssertAcquiredDebugOnly();
     return ++last_resource_id_;
   }
 
@@ -37,6 +45,7 @@ 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;
 
@@ -45,6 +54,7 @@ class PPAPI_PROXY_EXPORT CompositorResource
   virtual int32_t CommitLayers(
       const scoped_refptr<TrackedCallback>& callback) OVERRIDE;
   virtual int32_t ResetLayers() OVERRIDE;
+  virtual void BindToInstance(bool bound) OVERRIDE;
 
   // IPC msg handlers:
   void OnPluginMsgCommitLayersReply(const ResourceMessageReplyParams& params);
@@ -71,6 +81,8 @@ class PPAPI_PROXY_EXPORT CompositorResource
   typedef std::map<int32_t, ReleaseCallback> ReleaseCallbackMap;
   ReleaseCallbackMap release_callback_map_;
 
+  bool bound_to_instance_;
+
   // The last resource id for texture or image.
   mutable int32_t last_resource_id_;