Re-land^2 WebVR compositor bypass via BrowserMain context + mailbox

chrome/browser/android/vr_shell/vr_shell.h

Index: chrome/browser/android/vr_shell/vr_shell.h
diff --git a/chrome/browser/android/vr_shell/vr_shell.h b/chrome/browser/android/vr_shell/vr_shell.h
index b887d507962ac933825e72fdb61c8cbb94f1a8e3..eeb42cfccbefcafcc80163e9f9066d81425de3bf 100644
--- a/chrome/browser/android/vr_shell/vr_shell.h
+++ b/chrome/browser/android/vr_shell/vr_shell.h
@@ -17,6 +17,8 @@
 #include "content/public/browser/web_contents_observer.h"
 #include "device/vr/android/gvr/gvr_delegate.h"
 #include "device/vr/vr_service.mojom.h"
+#include "ui/android/context_provider_factory.h"
+#include "gpu/ipc/client/gpu_channel_host.h"
 #include "third_party/gvr-android-sdk/src/libraries/headers/vr/gvr/capi/include/gvr.h"
 #include "third_party/gvr-android-sdk/src/libraries/headers/vr/gvr/capi/include/gvr_types.h"
 
@@ -32,7 +34,14 @@ namespace content {
 class WebContents;
 }
 
+namespace gpu {
+namespace gles2 {
+class GLES2Interface;
+}
+}
+
 namespace ui {
+class ContextProviderCommandBuffer;
 class WindowAndroid;
 }
 
@@ -130,6 +139,8 @@ class VrShell : public device::GvrDelegate, content::WebContentsObserver {
 
   void UiSurfaceChanged(jobject surface);
   void ContentSurfaceChanged(jobject surface);
+  void WebVRSurfaceChanged(int surface_handle);
+  void WebVRFrameCompleted(int frame_index);
   void GvrDelegateReady();
   void AppButtonPressed();
 
@@ -184,7 +195,7 @@ class VrShell : public device::GvrDelegate, content::WebContentsObserver {
 
   // device::GvrDelegate implementation
   void SetWebVRSecureOrigin(bool secure_origin) override;
-  void SubmitWebVRFrame() override;
+  void SubmitWebVRFrame(int frame_index, const gpu::Mailbox& mailbox) override;
   void UpdateWebVRTextureBounds(int16_t frame_index,
                                 const gvr::Rectf& left_bounds,
                                 const gvr::Rectf& right_bounds) override;
@@ -200,11 +211,21 @@ class VrShell : public device::GvrDelegate, content::WebContentsObserver {
 
   void ProcessTabArray(JNIEnv* env, jobjectArray tabs, bool incognito);
 
+  void OnWebVrGpuChannelEstablished(
+      scoped_refptr<gpu::GpuChannelHost> gpu_channel_host,
+      ui::ContextProviderFactory::GpuChannelHostResult result);
+
   bool vr_shell_enabled_;
 
   std::unique_ptr<UiInterface> html_interface_;
   bool content_paused_ = false;
   bool webvr_mode_ = false;
+  int webvr_surface_handle_;
+  int webvr_frames_in_surface_queue_ = 0;
+
+  scoped_refptr<ui::ContextProviderCommandBuffer>
+      webvr_context_provider_command_buffer_;
+  gpu::gles2::GLES2Interface* webvr_surface_gl_ = nullptr;
 
   content::WebContents* main_contents_ = nullptr;
   base::android::ScopedJavaGlobalRef<jobject> j_motion_event_synthesizer_;