Use GVR async reprojection video surface for fullscreen in VR shell

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java

Index: chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java
index 47d59652794c7580512ef3572ba321554d334c34..990d455e3cd4448fe3d5aecb7b15fb45d465f1ff 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java
@@ -7,6 +7,8 @@ package org.chromium.chrome.browser.vr_shell;
 import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.graphics.Point;
+import android.os.Handler;
+import android.os.Looper;
 import android.os.StrictMode;
 import android.view.MotionEvent;
 import android.view.Surface;
@@ -76,6 +78,8 @@ public class VrShellImpl extends GvrLayout implements VrShell, SurfaceHolder.Cal
     private WindowAndroid mOriginalWindowAndroid;
     private VrWindowAndroid mContentVrWindowAndroid;
 
+    private Surface mExternalVideoSurface;
+
     private WebContents mUiContents;
     private ContentViewCore mUiCVC;
     private VrWindowAndroid mUiVrWindowAndroid;
@@ -93,6 +97,35 @@ public class VrShellImpl extends GvrLayout implements VrShell, SurfaceHolder.Cal
         };
         addView(mUiCVCContainer, 0, new FrameLayout.LayoutParams(0, 0));
 
+        ExternalSurfaceListener videoSurfaceListener =
+                new ExternalSurfaceListener() {
+                    @Override
+                    public void onSurfaceAvailable(Surface surface) {
+                        // This should be called after onResume if we were paused.
+
+                        // Hold onto this surface until full screen is initiated.
+                        mExternalVideoSurface = surface;
+
+                        // If we are waiting for a surface somehow (maybe if we full screen right as
+                        // we start and the surface hasn't come back yet) then we should have some
+                        // kind of resolver to send this surface down to the web media player as
+                        // soon as possible.
+                    }
+
+                    @Override
+                    public void onFrameAvailable() {
+                        // Do something here?
+                    }
+                };
+
+        // We must set the reprojection surface before enabling async reprojection.
+        // TODO(amp): Check the return value of this and don't return a surface id to the renderer
+        // if it didn't work.
+        enableAsyncReprojectionVideoSurface(
+                videoSurfaceListener,
+                new Handler(Looper.getMainLooper()),
+                true /* useProtectedBuffers */);
+
         mReprojectedRendering = setAsyncReprojectionEnabled(true);
         if (mReprojectedRendering) {
             // No need render to a Surface if we're reprojected. We'll be rendering with surfaceless
@@ -208,6 +241,50 @@ public class VrShellImpl extends GvrLayout implements VrShell, SurfaceHolder.Cal
         return cvc.getWindowAndroid().getViewRoot();
     }
 
+    @CalledByNative
+    public void createVideoSurface() {
+        // Send the previously created surface back down to the renderer.
+        // TODO(amp): Check that the surface was actually created succesfully.
+        VrShellImpl.this.nativeSetVideoSurface(mNativeVrShell, mExternalVideoSurface);
+
+        // Call into native code to configure the viewports?
+        // tell it to use the external surface and hide the content quad
+        // might need to pass in the surfaceId need for native variant of this call:
+        //    videoViewport.setExternalSurfaceId(gvrLayout.getAsyncReprojectionVideoSurfaceId());
+
+
+
+        // now we can configure the viewports referencing the external surface id
+
+        // Should this be on the native side (ie nativeDrawFrameOnGL)?
+
+        // The source UV coords of the video viewport should be the entire video frame.
+        //RectF videoUv = new RectF(/*left*/ 0.f, /*top*/ 1.f, /*right*/ 1.f, /*bottom*/ 0.f);
+
+        /*
+        configureViewports() = {
+          viewportList = gvrApi.createBufferViewportList();
+          recommendedViewportList = gvrApi.createBufferViewportList();
+          BufferViewport videoViewport = gvrApi.createBufferViewport();
+
+          // ... other configuring ...
+          gvrApi.getRecommendedBufferViewports(recommendedViewportList);
+          // Set up the video viewports.
+          for (int eye = 0; eye < 2; eye++) {
+            recommendedViewportList.get(eye, videoViewport);
+            videoViewport.setSourceBufferIndex(GvrApi.BUFFER_INDEX_EXTERNAL_SURFACE);
+            // This pulls the surface id that should have been created when the listener was
+            // created. It should have called back into native with this id.
+            videoViewport.setExternalSurfaceId(gvrLayout.getAsyncReprojectionVideoSurfaceId());
+            videoViewport.setTransform(videoTransform);
+            videoViewport.setSourceUv(videoUv);
+            viewportList.set(eye, videoViewport);
+          }
+        }
+
+        */
+    }
+
     @Override
     public boolean dispatchTouchEvent(MotionEvent event) {
         // Normally, touch event is dispatched to presentation view only if the phone is paired with
@@ -238,6 +315,9 @@ public class VrShellImpl extends GvrLayout implements VrShell, SurfaceHolder.Cal
     @Override
     public void onPause() {
         super.onPause();
+        // Drop the external video surface as it is no longer valid.
+        // TODO(amp): Should this be in shutdown instead? And is there a 'destroy' call to use?
+        mExternalVideoSurface = null;
         if (mNativeVrShell != 0) {
             nativeOnPause(mNativeVrShell);
         }
@@ -325,4 +405,5 @@ public class VrShellImpl extends GvrLayout implements VrShell, SurfaceHolder.Cal
     private native void nativeUIPhysicalBoundsChanged(long nativeVrShell, int width, int height,
             float dpr);
     private native void nativeSetWebVrMode(long nativeVrShell, boolean enabled);
+    private native void nativeSetVideoSurface(long nativeVrShell, Surface surface);
 }