PPAPI: Make GLES2 calls resilient to bad/dead resources.

ppapi/shared_impl/ppb_graphics_3d_shared.h

Index: ppapi/shared_impl/ppb_graphics_3d_shared.h
diff --git a/ppapi/shared_impl/ppb_graphics_3d_shared.h b/ppapi/shared_impl/ppb_graphics_3d_shared.h
index c51c99b81d11c3f302e8437900c0dce189f8be27..d576d57fa279c9059d2c37da4eb63dbc16545dd1 100644
--- a/ppapi/shared_impl/ppb_graphics_3d_shared.h
+++ b/ppapi/shared_impl/ppb_graphics_3d_shared.h
@@ -59,28 +59,6 @@ class PPAPI_SHARED_EXPORT PPB_Graphics3D_Shared
   void SwapBuffersACK(int32_t pp_error);
 
  protected:
-  // ScopedNoLocking makes sure we don't try to lock again when we already have
-  // the proxy lock. This is used when we need to use the CommandBuffer
-  // (possibly via gles2_impl) but we already have the proxy lock. The
-  // CommandBuffer in the plugin side of the proxy will otherwise try to acquire
-  // the ProxyLock, causing a crash because we already own the lock. (Locks in
-  // Chromium are never recursive).
-  class ScopedNoLocking {
-   public:
-    explicit ScopedNoLocking(PPB_Graphics3D_Shared* graphics3d_shared)
-        : graphics3d_shared_(graphics3d_shared) {
-      graphics3d_shared_->PushAlreadyLocked();
-    }
-    ~ScopedNoLocking() {
-      graphics3d_shared_->PopAlreadyLocked();
-    }
-   private:
-    PPB_Graphics3D_Shared* graphics3d_shared_;  // Weak
-
-    DISALLOW_COPY_AND_ASSIGN(ScopedNoLocking);
-  };
-
-
   PPB_Graphics3D_Shared(PP_Instance instance);
   PPB_Graphics3D_Shared(const HostResource& host_resource);
   virtual ~PPB_Graphics3D_Shared();
@@ -96,17 +74,6 @@ class PPAPI_SHARED_EXPORT PPB_Graphics3D_Shared
   void DestroyGLES2Impl();
 
  private:
-  // On the plugin side, we need to know that we already have the lock, so that
-  // we don't try to acquire it again. The default implementation does nothing;
-  // the Plugin side of the proxy must implement these.
-  friend class ScopedNoLocking;
-  virtual void PushAlreadyLocked();
-  virtual void PopAlreadyLocked();
-
-  // The VideoDecoder needs to be able to call Graphics3D Flush() after taking
-  // the proxy lock. Hence it needs access to ScopedNoLocking.
-  friend class PPB_VideoDecoder_Shared;
-
   scoped_ptr<gpu::gles2::GLES2CmdHelper> gles2_helper_;
   scoped_ptr<gpu::TransferBuffer> transfer_buffer_;
   scoped_ptr<gpu::gles2::GLES2Implementation> gles2_impl_;