VR: Prevent VR mode from being set on standalone VR devices.

VR is disabled on standalone devices, but the intent handling and
2D-in-VR support paths don't account for this and erroneously turn on
VR mode, or try to launch Chrome in VR, leaving the user stuck on a
black screen.

This CL ensures that we never set VR mode on standalone devices, and
forward VR intents back to the 2D launcher on these devices.

Change-Id: I3f8d41f66549f4c24e3056253299c10486f468df
Reviewed-on: https://chromium-review.googlesource.com/1003112
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Reviewed-by: Yash Malik <ymalik@chromium.org>
Cr-Commit-Position: refs/heads/master@{#549898}

chrome/android/java/src/org/chromium/chrome/browser/vr/VrMainActivity.java

@@ -5,6 +5,7 @@
 package org.chromium.chrome.browser.vr;
 
 import android.app.Activity;
+import android.content.Intent;
 import android.content.res.Configuration;
 import android.os.Build;
 import android.os.Bundle;
@@ -39,7 +40,19 @@ public class VrMainActivity extends Activity {
         try {
             super.onCreate(savedInstanceState);
 
-            if (!VrShellDelegate.isDaydreamReadyDevice()) {
+            // TODO(mthiesse, https://crbug.com/831175): Support WebVR launches on standalone VR
+            // devices.
+            if (!VrShellDelegate.deviceSupportsVrLaunches()) {
+                // If the device doesn't support VR launches, forward the intent back to the 2D
+                // launcher. We should only get here on standalone VR devices, or from bad intents
+                // probably sent by testers.
+                VrIntentUtils.removeVrExtras(getIntent());
+                getIntent().setComponent(null);
+                getIntent().setPackage(getPackageName());
+
+                // Daydream drops the MAIN action for unknown reasons...
+                if (getIntent().getAction() == null) getIntent().setAction(Intent.ACTION_MAIN);
+                startActivity(getIntent());
                 finish();
                 return;
             }

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

@@ -179,7 +179,7 @@ public class VrIntentUtils {
      */
     public static boolean maybeForwardToVrLauncher(Intent intent, Activity activity) {
         if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.O) return false;
-        if (wouldUse2DInVrRenderingMode(activity)) {
+        if (wouldUse2DInVrRenderingMode(activity) && VrShellDelegate.deviceSupportsVrLaunches()) {
             Intent vrIntent = new Intent(intent);
             vrIntent.setComponent(null);
             vrIntent.setPackage(activity.getPackageName());
@@ -214,7 +214,7 @@ public class VrIntentUtils {
     /**
      * Removes VR specific extras from the given intent to make it a non-VR intent.
      */
-    /* package */ static void removeVrExtras(Intent intent) {
+    public static void removeVrExtras(Intent intent) {
         if (intent == null) return;
         intent.removeCategory(DAYDREAM_CATEGORY);
         assert !isVrIntent(intent);

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

@@ -655,7 +655,10 @@ public class VrShellDelegate
      */
     public static void maybeHandleVrIntentPreNative(ChromeActivity activity, Intent intent) {
         if (!VrIntentUtils.isVrIntent(intent)) {
-            if (!VrIntentUtils.wouldUse2DInVrRenderingMode(activity)) return;
+            if (!VrIntentUtils.wouldUse2DInVrRenderingMode(activity)
+                    || !deviceSupportsVrLaunches()) {
+                return;
+            }
             // This is to handle intents that are sent directly to ChromeActivitys, bypassing the
             // launcher.
             intent.addCategory(VrIntentUtils.DAYDREAM_CATEGORY);
@@ -689,7 +692,7 @@ public class VrShellDelegate
      */
     public static void setVrModeEnabled(Activity activity, boolean enabled) {
         VrClassesWrapper wrapper = getVrClassesWrapper();
-        if (wrapper == null) return;
+        if (wrapper == null || wrapper.bootsToVr()) return;
         ensureLifecycleObserverInitialized();
         if (enabled) {
             if (sVrModeEnabledActivitys.contains(activity)) return;
@@ -864,6 +867,10 @@ public class VrShellDelegate
         return getVrClassesWrapper() != null && getVrClassesWrapper().isDaydreamReadyDevice();
     }
 
+    public static boolean deviceSupportsVrLaunches() {
+        return isDaydreamReadyDevice() && !getVrClassesWrapper().bootsToVr();
+    }
+
     // TODO(mthiesse): Should have package visibility only. We need to unify our vr and vr_shell
     // packages.
     public static boolean willChangeDensityInVr(ChromeActivity activity) {
@@ -930,7 +937,7 @@ public class VrShellDelegate
      *  @return Whether or not VR is supported on this platform.
      */
     /* package */ static boolean isVrEnabled() {
-        return getVrClassesWrapper() != null;
+        return getVrClassesWrapper() != null && !getVrClassesWrapper().bootsToVr();
     }
 
     private static void addBlackOverlayViewForActivity(ChromeActivity activity) {