Add ContextProvider::InvalidateGrContext to reset GL state in GrContext

cc/output/context_provider.cc

 // Copyright 2013 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 "cc/output/context_provider.h"
 
 #include <limits>
 
 namespace cc {
 
 ContextProvider::Capabilities::Capabilities()
     : max_transfer_buffer_usage_bytes(std::numeric_limits<size_t>::max()) {}
 
+void ContextProvider::InvalidateGrContext(uint32_t state) {
+  DoInvalidateGrContext(state);

[piman, 2015/05/06 22:03:40]

Why this?
Instead you can have each derived class implement InvalidateGrContext

[CodeByThePound, 2015/05/06 22:27:55]

This is a pattern that allows the default argument to InvalidateGrContext and
not have to propagate it through the derived classes.  If default arguments are
not allowed then this mechanism can be removed.

+}
+
 }  // namespace cc