Move gpu memory calculations to Compositor.

ui/compositor/test/in_process_context_provider.cc

Index: ui/compositor/test/in_process_context_provider.cc
diff --git a/ui/compositor/test/in_process_context_provider.cc b/ui/compositor/test/in_process_context_provider.cc
index 76cd19dc191ff8624982205a2d93b573b0058ecb..92fbf3a7b6e7bed567113adbe76b0039e62083c7 100644
--- a/ui/compositor/test/in_process_context_provider.cc
+++ b/ui/compositor/test/in_process_context_provider.cc
@@ -212,11 +212,6 @@ void InProcessContextProvider::SetLostContextCallback(
   lost_context_callback_ = lost_context_callback;
 }
 
-void InProcessContextProvider::SetMemoryPolicyChangedCallback(
-    const MemoryPolicyChangedCallback& memory_policy_changed_callback) {
-  // There's no memory manager for the in-process implementation.
-}
-
 void InProcessContextProvider::OnLostContext() {
   DCHECK(context_thread_checker_.CalledOnValidThread());
   {