Introduce ChromeVR to Chrome on Android (behind a build flag)

chrome/android/java/src/org/chromium/chrome/browser/ChromeVrActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ChromeVrActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeVrActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeVrActivity.java
new file mode 100644
index 0000000000000000000000000000000000000000..be403eea9d5b719308c1d83b5138f6bdc3b7a404
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeVrActivity.java
@@ -0,0 +1,77 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser;
+
+import android.graphics.PixelFormat;
+import android.graphics.SurfaceTexture;
+import android.view.View;
+import android.view.Window;
+import android.view.WindowManager;
+
+import org.chromium.chrome.browser.vr_shell.VrShell;
+
+/**
+ * A subclass of ChromeTabbedActivity, used in Daydream VR mode.
+ */
+public class ChromeVrActivity extends ChromeTabbedActivity {

[Maria, 2016/08/24 00:06:07]

It would help if there is a design doc you could share with me for this? Why do
you need all the stuff in ChromeTabbedActivity?

[Maria, 2016/08/24 00:06:07]

We actually try not to put Chrome before the activity name, I would rename this
to "VrActivity". Some of the ChromeBlah things are that way because of legacy
that cannot be changed.

[bshe, 2016/08/24 13:47:40]

Done.

[bshe, 2016/08/24 13:47:40]

Good point. I dont have a design doc for it. We don't need all the things in
ChromeTabbedActivity. The reason I use it here is that it is easier to start.
To do it correctly, I imagin that we will need to make changes in ChromeActivity
and then
extend from it. Or we may even need to modify ChromeTabbedActivity itself to
support the new VR mode. This is not going to be trivial and I don't want this
CL get much larger.
It is not perfect. But this code is behind a build time flag and wont affect
clank
in anyway. Given that, if you are fine with it, I will leave a TODO here and
create
a bug to track the process. The bug will block enable the build time flag.

[Maria, 2016/08/24 17:35:02]

Plan SGTM

+    private VrShell mVrShellView;
+
+    @Override
+    public void onResume() {
+        super.onResume();
+        mVrShellView.onResume();
+    }
+
+    @Override
+    public void onPause() {
+        super.onPause();
+        mVrShellView.onPause();
+    }
+
+    @Override
+    public void onDestroyInternal() {
+        super.onDestroyInternal();
+        if (mVrShellView != null) {
+            mVrShellView.shutdown();
+            mVrShellView = null;
+        }
+    }
+
+    @Override
+    public void initializeCompositor() {
+        super.initializeCompositor();
+        mVrShellView.onNativeLibraryReady();
+    }
+
+    @Override
+    public void postInflationStartup() {
+        super.postInflationStartup();
+        addVrViews();
+        setupVrModeWindowFlags();
+    }
+
+    public void replaceCompositorSurface(SurfaceTexture surfaceTexture) {
+        if (getCompositorViewHolder() != null) {
+            getCompositorViewHolder().replaceCompositorSurface(surfaceTexture);
+        }
+    }
+
+    private void addVrViews() {
+        mVrShellView = new VrShell(this);
+        WindowManager.LayoutParams params = new WindowManager.LayoutParams(
+                WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.MATCH_PARENT,
+                WindowManager.LayoutParams.TYPE_APPLICATION, 0, PixelFormat.OPAQUE);
+        this.addContentView(mVrShellView, params);
+    }
+
+    private void setupVrModeWindowFlags() {
+        Window window = getWindow();
+        window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
+        window.getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE
+                | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
+                | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_FULLSCREEN
+                | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
+    }
+}