Directly use GrGLInterface in cc tests rather than SkNullGLContext

cc/test/test_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/test/test_context_provider.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <set>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "cc/test/test_gles2_interface.h"
 #include "cc/test/test_web_graphics_context_3d.h"
 #include "third_party/skia/include/gpu/GrContext.h"
-#include "third_party/skia/include/gpu/gl/SkNullGLContext.h"
+#include "third_party/skia/include/gpu/gl/GrGLInterface.h"
 
 namespace cc {
 
 // static
 scoped_refptr<TestContextProvider> TestContextProvider::Create() {
   return Create(TestWebGraphicsContext3D::Create());
 }
 
 // static
 scoped_refptr<TestContextProvider> TestContextProvider::CreateWorker() {
@@ skipping 75 matching lines @@
   return &support_;
 }
 
 class GrContext* TestContextProvider::GrContext() {
   DCHECK(bound_);
   DCHECK(context_thread_checker_.CalledOnValidThread());
 
   if (gr_context_)
     return gr_context_.get();
 
-  scoped_ptr<class SkGLContext> gl_context(SkNullGLContext::Create());
-  gl_context->makeCurrent();
+  auto gl_interface = skia::AdoptRef(GrGLCreateNullInterface());

[danakj, 2016/03/25 18:09:36]

re: past chromium-dev threads, don't use auto for smart pointers.

[bsalomon, 2016/03/25 19:02:45]

Done.

   gr_context_ = skia::AdoptRef(GrContext::Create(
-      kOpenGL_GrBackend, reinterpret_cast<GrBackendContext>(gl_context->gl())));
+      kOpenGL_GrBackend,
+      reinterpret_cast<GrBackendContext>(gl_interface.get())));
 
   // If GlContext is already lost, also abandon the new GrContext.
   if (ContextGL()->GetGraphicsResetStatusKHR() != GL_NO_ERROR)
     gr_context_->abandonContext();
 
   return gr_context_.get();
 }
 
 void TestContextProvider::InvalidateGrContext(uint32_t state) {
   DCHECK(bound_);
@@ skipping 38 matching lines @@
   DCHECK(lost_context_callback_.is_null() || cb.is_null());
   lost_context_callback_ = cb;
 }
 
 void TestContextProvider::SetMaxTransferBufferUsageBytes(
     size_t max_transfer_buffer_usage_bytes) {
   context3d_->SetMaxTransferBufferUsageBytes(max_transfer_buffer_usage_bytes);
 }
 
 }  // namespace cc