Added the Vulkan Context Provider implementation.

cc/output/output_surface.cc

 // Copyright (c) 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/output_surface.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 143 matching lines @@
     : OutputSurface(std::move(context_provider),
                     std::move(worker_context_provider),
 #if defined(ENABLE_VULKAN)
                     nullptr,
 #endif
                     nullptr) {
 }
 
 #if defined(ENABLE_VULKAN)
 OutputSurface::OutputSurface(
-    scoped_refptr<VulkanContextProvider> vulkan_context_provider)
+    scoped_refptr<VulkanContextProvider> vulkan_context_provider,
+    bool use_vulkan)
     : OutputSurface(nullptr,
                     nullptr,
                     std::move(vulkan_context_provider),
-                    nullptr) {}
+                    nullptr) {
+  DCHECK(use_vulkan);
+}
 #endif
 
 OutputSurface::OutputSurface(
     std::unique_ptr<SoftwareOutputDevice> software_device)
     : OutputSurface(nullptr,
                     nullptr,
 #if defined(ENABLE_VULKAN)
                     nullptr,
 #endif
                     std::move(software_device)) {
@@ skipping 203 matching lines @@
   if (context_provider_.get()) {
     context_provider_->SetLostContextCallback(
         ContextProvider::LostContextCallback());
   }
   context_provider_ = nullptr;
   client_ = nullptr;
   weak_ptr_factory_.InvalidateWeakPtrs();
 }
 
 }  // namespace cc