Implement new compositor and ContentViewCore reparenting for VR Shell.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShell.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShell.java b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShell.java
index dd6c4d6cd6b96b0c5a2c9f85cfd09e5d1a8d5069..24949a8b478afc1b0f6bedfba4ca836812f614f3 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShell.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShell.java
@@ -12,18 +12,26 @@ import static android.opengl.GLES20.glGenTextures;
 import static android.opengl.GLES20.glTexParameteri;
 
 import android.app.Activity;
+import android.content.Context;
 import android.graphics.SurfaceTexture;
 import android.graphics.SurfaceTexture.OnFrameAvailableListener;
 import android.opengl.GLES11Ext;
 import android.opengl.GLSurfaceView;
 import android.os.StrictMode;
 import android.view.MotionEvent;
+import android.view.Surface;
+import android.view.ViewGroup;
 import android.widget.FrameLayout;
 
 import com.google.vr.ndk.base.AndroidCompat;
 import com.google.vr.ndk.base.GvrLayout;
 
+import org.chromium.base.ThreadUtils;
 import org.chromium.base.annotations.JNINamespace;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.content.browser.ContentViewCore;
+import org.chromium.content_public.browser.WebContents;
+import org.chromium.ui.base.WindowAndroid;
 
 import javax.microedition.khronos.egl.EGLConfig;
 import javax.microedition.khronos.opengles.GL10;
@@ -46,9 +54,35 @@ public class VrShell extends GvrLayout implements GLSurfaceView.Renderer, VrShel
     private int mContentTextureHandle;
     private FrameListener mContentFrameListener;
 
+    private ContentViewCoreHolder mContentViewCoreHolder;

[Ted C, 2016/09/20 19:57:07]

Container is probably a more common word than Holder for a View construct

[mthiesse, 2016/09/20 20:56:08]

Done.

+
+    // The tab that holds the main ContentViewCore.
+    private Tab mContentTab;
+    // The ContentViewCore for the main content rect in VR.
+    private ContentViewCore mContentCVC;

[Ted C, 2016/09/20 19:57:06]

mCVC is all you need

[mthiesse, 2016/09/20 20:56:08]

Done.

+    // The parent of the @ContentView for mContentContentViewCore.

[Ted C, 2016/09/20 19:57:07]

Non-standard comment.

I think, "The non-VR container view for mContentCVC" is probably better. 
ContentContentViewParent also is a bit weird.  Maybe TabContentViewParent or
mOriginalContentViewParent (which would better align with your WindowAndroid
naming)

[mthiesse, 2016/09/20 20:56:07]

Done.

+    private ViewGroup mContentCVParent;
+    private VrWindowAndroid mContentVRWindowAndroid;

[Ted C, 2016/09/20 19:57:06]

mVRWindowAndroid is sufficient

[mthiesse, 2016/09/20 20:56:07]

Done.

+    private WindowAndroid mOldContentWindowAndroid;
+
+    private static class ContentViewCoreHolder extends FrameLayout {
+        public ContentViewCoreHolder(Context context) {
+            super(context);
+        }
+
+        @Override
+        public boolean dispatchTouchEvent(MotionEvent event) {
+            return true;
+        }
+    }
+
     public VrShell(Activity activity) {
         super(activity);
         mActivity = activity;
+        mContentViewCoreHolder = new ContentViewCoreHolder(activity);
+        addView(mContentViewCoreHolder, 0, new FrameLayout.LayoutParams(
+                FrameLayout.LayoutParams.MATCH_PARENT,
+                FrameLayout.LayoutParams.MATCH_PARENT));
         mGlSurfaceView = new GLSurfaceView(getContext());
         mGlSurfaceView.setEGLContextClientVersion(2);
         mGlSurfaceView.setEGLConfigChooser(8, 8, 8, 8, 0, 0);
@@ -62,8 +96,42 @@ public class VrShell extends GvrLayout implements GLSurfaceView.Renderer, VrShel
     }
 
     @Override
-    public void onNativeLibraryReady() {
-        mNativeVrShell = nativeInit();
+    public void onNativeLibraryReady(Tab currentTab) {
+        assert currentTab.getContentViewCore() != null;
+        mContentTab = currentTab;
+        mContentCVC = mContentTab.getContentViewCore();
+        mContentVRWindowAndroid = new VrWindowAndroid(mActivity);
+
+        mNativeVrShell = nativeInit(mContentCVC.getWebContents(),
+                mContentVRWindowAndroid.getNativePointer());
+
+        reparentContentWindow();
+
+        nativeUpdateCompositorLayers(mNativeVrShell);
+    }
+
+    private void reparentContentWindow() {
+        mOldContentWindowAndroid = mContentCVC.getWindowAndroid();
+
+        // TODO(mthiesse): Update the WindowAndroid in ChromeActivity too?
+        mContentTab.updateWindowAndroid(mContentVRWindowAndroid);
+
+        ViewGroup contentContentView = mContentCVC.getContainerView();
+        mContentCVParent = ((ViewGroup) contentContentView.getParent());
+        mContentCVParent.removeView(contentContentView);
+
+        mContentViewCoreHolder.addView(contentContentView, new FrameLayout.LayoutParams(
+                FrameLayout.LayoutParams.MATCH_PARENT,
+                FrameLayout.LayoutParams.MATCH_PARENT));
+    }
+
+    private void restoreContentWindow() {
+        ViewGroup contentContentView = mContentCVC.getContainerView();
+        mContentTab.updateWindowAndroid(mOldContentWindowAndroid);
+        mContentViewCoreHolder.removeView(contentContentView);
+        mContentCVParent.addView(contentContentView, new FrameLayout.LayoutParams(

[Ted C, 2016/09/20 19:57:07]

this is not a safe call to do.  You are wiping out the previous layout params
and index as part of this.

We either need to cache both of these (or figure out a way to use the existing
reparenting path).  In the multiple activity approach, we'll need to make
reparenting work for this, so we might want to see if we can just do it now.

If not, cache this and add a TODO to replace with proper reparenting.

[mthiesse, 2016/09/20 20:56:08]

For now I'll cache with a TODO. I briefly looked into properly using reparenting
when implementing this patch and it looks like it'll be pretty non-trivial.

+                FrameLayout.LayoutParams.MATCH_PARENT,
+                FrameLayout.LayoutParams.MATCH_PARENT));
     }
 
     private static class FrameListener implements OnFrameAvailableListener {
@@ -96,9 +164,21 @@ public class VrShell extends GvrLayout implements GLSurfaceView.Renderer, VrShel
 
     @Override
     public void onSurfaceCreated(GL10 gl, EGLConfig config) {
+        final int width = mContentCVC.getContainerView().getWidth();
+        final int height = mContentCVC.getContainerView().getHeight();
         mContentTextureHandle = createExternalTextureHandle();
         mContentFrameListener = new FrameListener(new SurfaceTexture(mContentTextureHandle),
                 mGlSurfaceView);
+        mContentFrameListener.mSurfaceTexture.setDefaultBufferSize(width, height);
+
+        ThreadUtils.postOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                nativeContentSurfaceChanged(mNativeVrShell, width, height,
+                        new Surface(mContentFrameListener.mSurfaceTexture));
+                mContentCVC.onPhysicalBackingSizeChanged(width, height);
+            }
+        });
 
         nativeGvrInit(mNativeVrShell, getGvrApi().getNativeGvrContext());
         nativeInitializeGl(mNativeVrShell, mContentTextureHandle);
@@ -152,6 +232,7 @@ public class VrShell extends GvrLayout implements GLSurfaceView.Renderer, VrShel
         if (mContentFrameListener != null && mContentFrameListener.mSurfaceTexture != null) {
             mContentFrameListener.mSurfaceTexture.release();
         }
+        restoreContentWindow();
     }
 
     @Override
@@ -201,7 +282,8 @@ public class VrShell extends GvrLayout implements GLSurfaceView.Renderer, VrShel
         }
     }
 
-    private native long nativeInit();
+    private native long nativeInit(WebContents contentWebContents,
+            long nativeContentWindowAndroid);
 
     private native void nativeGvrInit(long nativeVrShell, long nativeGvrApi);
 
@@ -215,4 +297,11 @@ public class VrShell extends GvrLayout implements GLSurfaceView.Renderer, VrShel
     private native void nativeOnPause(long nativeVrShell);
 
     private native void nativeOnResume(long nativeVrShell);
+
+    private native void nativeContentSurfaceDestroyed(long nativeVrShell);
+
+    private native void nativeContentSurfaceChanged(
+            long nativeVrShell, int width, int height, Surface surface);
+
+    private native void nativeUpdateCompositorLayers(long nativeVrShell);
 }