VR: Ensure initial paused state is set correctly for VrShellDelegate.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
index 12629870dc2b0462e70aff9eee2dc6f36bbbee66..0d1ef6389e475d33ce782cf23150cd5bee8b007f 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
@@ -361,6 +361,8 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
     private VrShellDelegate(ChromeActivity activity, VrClassesWrapper wrapper) {
         mActivity = activity;
         mVrClassesWrapper = wrapper;
+        // If an activity isn't resumed at the point, it must have been paused.
+        mPaused = ApplicationStatus.getStateForActivity(activity) != ActivityState.RESUMED;
         updateVrSupportLevel();
         mNativeVrShellDelegate = nativeInit();
         Choreographer choreographer = Choreographer.getInstance();
@@ -386,6 +388,8 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
                 break;
             case ActivityState.PAUSED:
                 if (activity == mActivity) pauseVr();
+                // Other activities should only pause while we're paused due to Android lifecycle.
+                assert mPaused;
                 break;
             case ActivityState.RESUMED:
                 assert !mInVr;