mac: Finish plumbing for Pepper3D Image Chromium.

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 7e11f6cd526390085fa470f15f35260654834ce4..f42aec0a559b224335b841106f64ee0e228c1d1d 100644
--- a/ppapi/shared_impl/ppb_graphics_3d_shared.h
+++ b/ppapi/shared_impl/ppb_graphics_3d_shared.h
@@ -78,11 +78,21 @@ class PPAPI_SHARED_EXPORT PPB_Graphics3D_Shared
                        gpu::gles2::GLES2Implementation* share_gles2);
   void DestroyGLES2Impl();
 
+  // Must be called by this class or subclasses any time the viewport size
+  // changes.
+  void SetSize(int32_t width, int32_t height);
+  int32_t width() { return width_; }
+  int32_t height() { return height_; }
+
  private:
   std::unique_ptr<gpu::gles2::GLES2CmdHelper> gles2_helper_;
   std::unique_ptr<gpu::TransferBuffer> transfer_buffer_;
   std::unique_ptr<gpu::gles2::GLES2Implementation> gles2_impl_;
 
+  // A local cache of the size of the viewport.
+  int32_t width_ = 0;
+  int32_t height_ = 0;
+
   // Callback that needs to be executed when swap-buffers is completed.
   scoped_refptr<TrackedCallback> swap_callback_;