Fix a focus issue for VR headset activation.

The bug here is that we aren't updating whether to listen for headset
activation when focus changes.

BUG=846661

Change-Id: I029099a6de8b8337d51aa210ad58165fbd01a050
Reviewed-on: https://chromium-review.googlesource.com/1074742
Reviewed-by: Bill Orr <billorr@chromium.org>
Reviewed-by: Michael Thiessen <mthiesse@chromium.org>
Commit-Queue: Bill Orr <billorr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562282}

chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/WebVrInputTest.java

@@ -34,7 +34,6 @@
 import org.chromium.base.test.params.ParameterizedRunner;
 import org.chromium.base.test.util.CommandLineFlags;
 import org.chromium.base.test.util.DisableIf;
-import org.chromium.base.test.util.DisabledTest;
 import org.chromium.base.test.util.MinAndroidSdkLevel;
 import org.chromium.base.test.util.Restriction;
 import org.chromium.base.test.util.RetryOnFailure;
@@ -563,7 +562,6 @@ public Boolean call() throws Exception {
      * Tests that focus loss updates synchronously.
      */
     @Test
-    @DisabledTest(message = "https://crbug.com/846661")
     @MediumTest
     @Restriction(RESTRICTION_TYPE_VIEWER_DAYDREAM)
     @VrActivityRestriction({VrActivityRestriction.SupportedActivity.ALL})

chrome/browser/vr/service/vr_display_host.cc

@@ -120,6 +120,7 @@ void VRDisplayHost::SetListeningForActivate(bool listening) {
 
 void VRDisplayHost::SetInFocusedFrame(bool in_focused_frame) {
   in_focused_frame_ = in_focused_frame;
+  browser_device_->UpdateListeningForActivate(this);
   display_->SetInFocusedFrame(in_focused_frame);
 }