VR: Make sure VR is fully entered before proceeding in tests.

Bug: 746504
Change-Id: Ia7296889916aac759edfef72c34beb01770d79ca
Reviewed-on: https://chromium-review.googlesource.com/581851Reviewed-by: Yash Malik <ymalik@chromium.org>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488757}

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

@@ -538,15 +538,15 @@ public class VrShellDelegate
             public void doFrame(long frameTimeNanos) {
                 if (mNativeVrShellDelegate == 0) return;
                 Choreographer.getInstance().postFrameCallback(this);
-                ++mVSyncCount;
                 if (mVSyncTimebaseNanos == 0) {
                     updateVSyncInterval(frameTimeNanos, mVSyncIntervalNanos);
                     return;
                 }
-                if (mVSyncCount < MIN_FRAME_COUNT) return;
+                ++mVSyncCount;
                 long elapsed = frameTimeNanos - mVSyncTimebaseNanos;
                 // If you're hitting the assert below, you probably added the callback twice.
                 assert elapsed != 0;
+                if (mVSyncCount < MIN_FRAME_COUNT) return;
                 long vSyncIntervalNanos = elapsed / mVSyncCount;
                 if (vSyncIntervalNanos < mMinVSyncIntervalNanos) {
                     // We may run slow, but we should never run fast. If the VSync interval is too
@@ -1587,6 +1587,11 @@ public class VrShellDelegate
         return nativeIsClearActivatePending(mNativeVrShellDelegate);
     }
 
+    @VisibleForTesting
+    public boolean isVrEntryComplete() {
+        return mInVr && !mProbablyInDon;
+    }
+
     /**
      * @return Pointer to the native VrShellDelegate object.
      */

chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/util/VrTransitionUtils.java

@@ -67,7 +67,7 @@ public class VrTransitionUtils {
         CriteriaHelper.pollUiThread(Criteria.equals(true, new Callable<Boolean>() {
             @Override
             public Boolean call() {
-                return VrShellDelegate.isInVr();
+                return VrShellDelegate.getInstanceForTesting().isVrEntryComplete();
             }
         }), timeout, POLL_CHECK_INTERVAL_SHORT_MS);
     }
@@ -111,8 +111,8 @@ public class VrTransitionUtils {
      */
     public static void enterPresentationOrFail(ContentViewCore cvc) {
         enterPresentation(cvc);
-        VrTestRule.pollJavaScriptBoolean(
-                "vrDisplay.isPresenting", POLL_TIMEOUT_LONG_MS, cvc.getWebContents());
+        Assert.assertTrue(VrTestRule.pollJavaScriptBoolean(
+                "vrDisplay.isPresenting", POLL_TIMEOUT_LONG_MS, cvc.getWebContents()));
         Assert.assertTrue(VrShellDelegate.getVrShellForTesting().getWebVrModeEnabled());
     }