Replace context parenting by sharing through mailboxes

content/common/gpu/client/command_buffer_proxy_impl.cc

Index: content/common/gpu/client/command_buffer_proxy_impl.cc
diff --git a/content/common/gpu/client/command_buffer_proxy_impl.cc b/content/common/gpu/client/command_buffer_proxy_impl.cc
index 47b4ce087f5db072e97addec2604e472af721018..cde985544c29754b5f8485c0c916486f4092a4d7 100644
--- a/content/common/gpu/client/command_buffer_proxy_impl.cc
+++ b/content/common/gpu/client/command_buffer_proxy_impl.cc
@@ -444,32 +444,11 @@ bool CommandBufferProxyImpl::GenerateMailboxNames(
   return channel_->GenerateMailboxNames(num, names);
 }
 
-bool CommandBufferProxyImpl::SetParent(
-    CommandBufferProxy* parent_command_buffer,
-    uint32 parent_texture_id) {
+bool CommandBufferProxyImpl::ProduceFrontBuffer(const gpu::Mailbox& mailbox) {
   if (last_state_.error != gpu::error::kNoError)
     return false;
 
-  bool result;
-  if (parent_command_buffer) {
-    if (!Send(new GpuCommandBufferMsg_SetParent(
-        route_id_,
-        parent_command_buffer->GetRouteID(),
-        parent_texture_id,
-        &result))) {
-      return false;
-    }
-  } else {
-    if (!Send(new GpuCommandBufferMsg_SetParent(
-        route_id_,
-        MSG_ROUTING_NONE,
-        0,
-        &result))) {
-      return false;
-    }
-  }
-
-  return result;
+  return Send(new GpuCommandBufferMsg_ProduceFrontBuffer(route_id_, mailbox));
 }
 
 scoped_ptr<media::VideoDecodeAccelerator>