Clarify/fix fullscreen semantics, and add GetScreenSize

webkit/plugins/ppapi/ppb_surface_3d_impl.cc

 // Copyright (c) 2010 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.
 
 #include "webkit/plugins/ppapi/ppb_surface_3d_impl.h"
 
 #include "gpu/command_buffer/client/gles2_implementation.h"
 #include "gpu/command_buffer/common/command_buffer.h"
 #include "ppapi/c/dev/ppb_graphics_3d_dev.h"
 #include "webkit/plugins/ppapi/common.h"
@@ skipping 126 matching lines @@
 
   swap_callback_ = callback;
   gpu::gles2::GLES2Implementation* impl = context_->gles2_impl();
   if (impl) {
     context_->gles2_impl()->SwapBuffers();
   }
   return PP_ERROR_WOULDBLOCK;
 }
 
 void PPB_Surface3D_Impl::ViewInitiatedPaint() {
-  if (swap_callback_.func) {
-    swap_initiated_ = true;
-  }
 }
 
 void PPB_Surface3D_Impl::ViewFlushedPaint() {
   if (swap_initiated_ && swap_callback_.func) {
     // We must clear swap_callback_ before issuing the callback. It will be
     // common for the plugin to issue another SwapBuffers in response to the
     // callback, and we don't want to think that a callback is already pending.
     PP_CompletionCallback callback = PP_BlockUntilComplete();
     std::swap(callback, swap_callback_);
     swap_initiated_ = false;
     PP_RunCompletionCallback(&callback, PP_OK);
   }
 }
 
 unsigned int PPB_Surface3D_Impl::GetBackingTextureId() {
   return context_ ? context_->platform_context()->GetBackingTextureId() : 0;
 }
 
 void PPB_Surface3D_Impl::OnSwapBuffers() {
-  if (bound_to_instance_)
+  if (bound_to_instance_) {
     instance()->CommitBackingTexture();
+    swap_initiated_ = true;
+  } else if (swap_callback_.func) {
+    // If we're off-screen, no need to trigger compositing so run the callback
+    // immediately.
+    PP_CompletionCallback callback = PP_BlockUntilComplete();
+    std::swap(callback, swap_callback_);
+    swap_initiated_ = false;
+    PP_RunCompletionCallback(&callback, PP_OK);
+  }
 }
 
 }  // namespace ppapi
 }  // namespace webkit