Add ContextProvider overrides to SynchronousCompositorFactory

content/renderer/pepper/pepper_platform_context_3d_impl.cc

Index: content/renderer/pepper/pepper_platform_context_3d_impl.cc
diff --git a/content/renderer/pepper/pepper_platform_context_3d_impl.cc b/content/renderer/pepper/pepper_platform_context_3d_impl.cc
index ffa3d2d86005e608f4b061bec657128a1efcb709..8553362a48f39b628aa832f9342f0599c5665efa 100644
--- a/content/renderer/pepper/pepper_platform_context_3d_impl.cc
+++ b/content/renderer/pepper/pepper_platform_context_3d_impl.cc
@@ -125,8 +125,9 @@ bool PlatformContext3DImpl::SetParentAndCreateBackingTextureIfNeeded() {
       parent_texture_id_)
     return true;
 
-  parent_context_provider_ =
-      RenderThreadImpl::current()->OffscreenContextProviderForMainThread();
+  parent_context_provider_ = static_cast<ContextProviderCommandBuffer*>(

[joth, 2013/06/02 19:08:55]

could we change parent_context_provider_  to be a base-class pointer rather than
cast here? AFAICT the public APIs are the same, so it's just a matter of who
else does this get passed to that also expects subclass pointer...

[boliu, 2013/06/03 18:51:24]

ContextProvider api is the almost same, just the CB provider returns a CB
context. But the public api on the context is not the same: GetImplementation
and GetCommandBufferProxy are not on the in-process context.

I think GetCommandBufferProxy in particular implies cross-process context, and
this has its own command_buffer_ of the same class. So unless we rewrite this
code to not hardcode this class, a cast is needed in this file somewhere.

No idea how hard this rewrite actually is.

+      RenderThreadImpl::current()->OffscreenContextProviderForMainThread()
+          .get());
   parent_texture_id_ = 0;
   if (!parent_context_provider_)
     return false;