Lower runtime of one VR test

Switches WebVrTransitionTEst#testControlsVisibleAfterExitingVr to use
enterPresentationOrFail, as before it was waiting for a non-existent
JavaScript step to finish, which added ~10 seconds onto each test run.

Bug: 
Change-Id: I2170941f78ac900b9dde57ac9fa5d70cdd43c8c0
Reviewed-on: https://chromium-review.googlesource.com/806247Reviewed-by: Michael Thiessen <mthiesse@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521520}

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

@@ -212,8 +212,7 @@ public class WebVrTransitionTest {
     public void testControlsVisibleAfterExitingVr() throws InterruptedException {
         mVrTestFramework.loadUrlAndAwaitInitialization(
                 VrTestFramework.getHtmlTestFile("generic_webvr_page"), PAGE_LOAD_TIMEOUT_S);
-        VrTransitionUtils.enterPresentationAndWait(
-                mVrTestFramework.getFirstTabCvc(), mVrTestFramework.getFirstTabWebContents());
+        VrTransitionUtils.enterPresentationOrFail(mVrTestFramework.getFirstTabCvc());
         VrTransitionUtils.forceExitVr();
         // The hiding of the controls may only propagate after VR has exited, so give it a chance
         // to propagate. In the worst case this test will erroneously pass, but should never