Added initial implementation of Vulkan Render Passes.

content/common/gpu/gpu_command_buffer_stub.h

Index: content/common/gpu/gpu_command_buffer_stub.h
diff --git a/content/common/gpu/gpu_command_buffer_stub.h b/content/common/gpu/gpu_command_buffer_stub.h
index e20388717304d1dbd9fa84780a07431e22a5661a..38eaa2a2b3e034e0ca7a6366ba0909d6107f5287 100644
--- a/content/common/gpu/gpu_command_buffer_stub.h
+++ b/content/common/gpu/gpu_command_buffer_stub.h
@@ -37,6 +37,12 @@
 #include "url/gurl.h"
 
 namespace gpu {
+#if defined(ENABLE_VULKAN)
+class VulkanSurface;
+#endif
+}
+
+namespace gpu {
 struct Mailbox;
 struct SyncToken;
 class SyncPointClient;
@@ -259,6 +265,9 @@ class GpuCommandBufferStub
   scoped_ptr<gpu::GpuScheduler> scheduler_;
   scoped_ptr<gpu::SyncPointClient> sync_point_client_;
   scoped_refptr<gfx::GLSurface> surface_;
+#if defined(ENABLE_VULKAN)
+  scoped_ptr<gpu::VulkanSurface> vk_surface_;
+#endif
   gfx::GLSurface::Format surface_format_;
 
   GpuWatchdog* watchdog_;