Added the Vulkan Context Provider implementation.

content/browser/compositor/gpu_process_transport_factory.h

Index: content/browser/compositor/gpu_process_transport_factory.h
diff --git a/content/browser/compositor/gpu_process_transport_factory.h b/content/browser/compositor/gpu_process_transport_factory.h
index 1996a848f2689d104b9d63d7bf0bbe55f8a55e68..0343c46055c9e15cb1b37827e9d4a0b7d8a9ba47 100644
--- a/content/browser/compositor/gpu_process_transport_factory.h
+++ b/content/browser/compositor/gpu_process_transport_factory.h
@@ -30,6 +30,7 @@ namespace cc {
 class SingleThreadTaskGraphRunner;
 class SoftwareOutputDevice;
 class SurfaceManager;
+class VulkanInProcessContextProvider;
 }
 
 namespace content {
@@ -101,6 +102,11 @@ class GpuProcessTransportFactory
   void OnLostMainThreadSharedContextInsideCallback();
   void OnLostMainThreadSharedContext();
 
+#if defined(ENABLE_VULKAN)

[piman, 2016/04/19 01:36:42]

Trying to find a way to limit the amount of #ifdef we need... in terms of
interface, VulkanInProcessContextProvider doesn't need Vulkan types explicitly,
maybe we can remove the ifdef here, and limit it to the implementation of
VulkanInProcessContextProvider (i.e. have Initialize fail)

[David Yen, 2016/04/19 22:20:28]

Done. The only thing is we still have to #ifdef out
VulkanBrowserCompositorOutputSurface, so there is a bit of a mismatch going on
there. A little strange but it works out I think.

If we are going to compile in VulkanInProcessContextProvider, perhaps we should
also remove the #ifdefs in OutputSurface? We discussed that before and decided
not to so that we wouldn't have to compile in that file. But since we are
already including it I think we might as well. What do you think?

[piman, 2016/04/19 23:29:57]

Yeah, I think I agree. I'm thinking that eventually we'll want to dynamically
load the loader anyway, at which point everything can compile, even on platforms
where Vulkan is not supported. We may want to keep a #ifdef in the lower levels
to avoid bringing too much code, but if we can avoid it in the higher levels,
it's probably more readable.

+  scoped_refptr<cc::VulkanInProcessContextProvider>
+  SharedVulkanContextProvider();
+#endif
+
   typedef std::map<ui::Compositor*, PerCompositorData*> PerCompositorDataMap;
   PerCompositorDataMap per_compositor_data_;
   scoped_refptr<ContextProviderCommandBuffer> shared_main_thread_contexts_;
@@ -111,6 +117,12 @@ class GpuProcessTransportFactory
   std::unique_ptr<cc::SingleThreadTaskGraphRunner> task_graph_runner_;
   scoped_refptr<ContextProviderCommandBuffer> shared_worker_context_provider_;
 
+#if defined(ENABLE_VULKAN)
+  bool shared_vulkan_context_provider_initialized_ = false;
+  scoped_refptr<cc::VulkanInProcessContextProvider>
+      shared_vulkan_context_provider_;
+#endif
+
 #if defined(OS_WIN)
   std::unique_ptr<OutputDeviceBacking> software_backing_;
 #endif