Revert "VR: Cancel stay_hidden animation when VR UI is ready to be shown."

This reverts commit 50a17030.

Reason for revert: https://bugs.chromium.org/p/chromium/issues/detail?id=741761

Original change's description:
> VR: Cancel stay_hidden animation when VR UI is ready to be shown.
> 
> This replaces hugely hacky behaviour where we assumed Chrome would start
> up within 500ms because we couldn't figure out how to cancel the
> activity animation, with only moderately hacky behaviour where we start
> a noDisplay activity in order to cancel the animation.
> 
> The duration of the stay_hidden animation has been increased to the max
> duration of 10s, giving chrome ample time to start up while hidden and
> then cancel the animation.
> 
> Bug: 740004
> Change-Id: I0f2c8daac7b0f692f0ed5a9bbfefe29a925811e6
> Reviewed-on: https://chromium-review.googlesource.com/567336
> Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
> Reviewed-by: Yash Malik <ymalik@chromium.org>
> Reviewed-by: David Trainor <dtrainor@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#485980}

TBR=mthiesse@chromium.org,dtrainor@chromium.org,ymalik@chromium.org

Change-Id: Iee18c28ac9a047e0e281ed6fe5defd0cde1eec9a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 740004
Reviewed-on: https://chromium-review.googlesource.com/568638Reviewed-by: Michael Thiessen <mthiesse@chromium.org>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/master@{#486015}

chrome/android/java/AndroidManifest.xml

@@ -619,16 +619,6 @@ by a child template that "extends" this file.
             android:excludeFromRecents="true">
         </activity>
 
-        <activity
-            android:name="org.chromium.chrome.browser.vr_shell.VrCancelAnimationActivity"
-            android:exported="false"
-            android:theme="@android:style/Theme.NoDisplay"
-            android:noHistory="true"
-            android:excludeFromRecents="true"
-            android:enableVrMode="@string/gvr_vr_mode_component">
-            {{ self.supports_vr() }}
-        </activity>
-
         <!-- Service for handling Nearby Messages -->
         <service android:name="org.chromium.chrome.browser.physicalweb.NearbyMessageIntentService"
             android:exported="false" />

chrome/android/java/res/anim/stay_hidden.xml

@@ -6,8 +6,10 @@
 
 <!-- The delay here must be long enough for the Activity being resumed to draw
      its first frame of UI. This is to avoid showing stale 2D screenshots when
-     launching Chrome in VR. We cancel this animation upon entering VR. -->
+     launching Chrome in VR. Note that the larger this value is, the more
+     latency we add to resuming Chrome after going through the Daydream Device
+     ON flow. -->
 <alpha xmlns:android="http://schemas.android.com/apk/res/android"
         android:interpolator="@android:anim/linear_interpolator"
         android:fromAlpha="0" android:toAlpha="0"
-        android:duration="10000" />
+        android:duration="500" />

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

-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package org.chromium.chrome.browser.vr_shell;
-
-import android.app.Activity;
-import android.os.Bundle;
-
-/**
- * Cancel the startActivity animation used to keep 2D UI hidden while Chrome is starting up.
- * See the comments in VrShellDelegate.VrBroadcastReceiver#onReceive for more information.
- */
-public class VrCancelAnimationActivity extends Activity {
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        finish();
-        overridePendingTransition(0, 0);
-    }
-}
\ No newline at end of file

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

@@ -136,8 +136,6 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
     private final Handler mEnterVrHandler;
     private final Handler mExpectPauseOrDonSucceeded;
     private boolean mProbablyInDon;
-    private boolean mNeedsAnimationCancel;
-    private boolean mCancellingEntryAnimation;
 
     // Whether or not the VR Device ON flow succeeded. If this is true it means the user has a VR
     // headset on, but we haven't switched into VR mode yet.
@@ -198,12 +196,13 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
                 // However, if we're already in VR (in one of the cases where we chose not to exit
                 // VR before the DON flow), we don't need to add the overlay.
                 if (!sInstance.mInVr) sInstance.addOverlayView();
-                sInstance.mNeedsAnimationCancel = !sInstance.mInVr;
 
-                // We start the Activity with a custom animation that keeps it hidden while starting
-                // up to avoid Android showing stale 2D screenshots when the user is in their VR
-                // headset. The animation lasts up to 10 seconds, but is cancelled when we're
-                // resumed as at that time we'll be showing the black overlay added above.
+                // We start the Activity with a custom animation that keeps it hidden for a few
+                // hundred milliseconds - enough time for us to draw the first black view.
+                // TODO(mthiesse): This is really hacky. If we can find a way to cancel the
+                // transition animation (I couldn't), then we can just make it indefinite until the
+                // VR UI is ready, and then cancel it, rather than trying to guess how long it will
+                // take to draw the first view, and possibly adding latency to VR startup.
                 int animation = sInstance.mInVr ? 0 : R.anim.stay_hidden;
                 Bundle options =
                         ActivityOptions.makeCustomAnimation(activity, animation, 0).toBundle();
@@ -592,9 +591,6 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
             case ActivityState.STOPPED:
                 if (activity == mActivity) onStop();
                 break;
-            case ActivityState.STARTED:
-                if (activity == mActivity) onStart();
-                break;
             case ActivityState.RESUMED:
                 if (mInVr && activity != mActivity) {
                     if (mShowingDaydreamDoff) {
@@ -714,7 +710,6 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
             cancelPendingVrEntry();
             return;
         }
-        mVrClassesWrapper.setVrModeEnabled(mActivity, true);
         if (!isWindowModeCorrectForVr()) {
             setWindowModeForVr(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
             mEnterVrHandler.post(new Runnable() {
@@ -747,11 +742,12 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
         mDonSucceeded = false;
         if (!createVrShell()) {
             maybeSetPresentResult(false, donSuceeded);
+            mVrDaydreamApi.launchVrHomescreen();
             cancelPendingVrEntry();
             mInVr = false;
-            mVrDaydreamApi.launchVrHomescreen();
             return;
         }
+        mVrClassesWrapper.setVrModeEnabled(mActivity, true);
         mShouldShowPageInfo = false;
         shutdownNonPresentingNativeContext();
 
@@ -777,7 +773,6 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
         maybeSetPresentResult(true, donSuceeded);
         mVrShell.getContainer().setOnSystemUiVisibilityChangeListener(this);
         removeOverlayView();
-
         if (!donSuceeded && !mAutopresentWebVr && isDaydreamCurrentViewer()) {
             // TODO(mthiesse): This is a VERY dirty hack. We need to know whether or not entering VR
             // will trigger the DON flow, so that we can wait for it to complete before we let the
@@ -897,9 +892,7 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
      */
     @EnterVRResult
     private int enterVrInternal() {
-        if (mPaused) return ENTER_VR_CANCELLED;
         if (mInVr) return ENTER_VR_NOT_NECESSARY;
-
         // Update VR support level as it can change at runtime
         updateVrSupportLevel();
         if (mVrSupportLevel == VR_NOT_AVAILABLE) return ENTER_VR_CANCELLED;
@@ -925,14 +918,6 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
     }
 
     private void onResume() {
-        if (mNeedsAnimationCancel) {
-            mCancellingEntryAnimation = true;
-            Bundle options = ActivityOptions.makeCustomAnimation(mActivity, 0, 0).toBundle();
-            mActivity.startActivity(
-                    new Intent(mActivity, VrCancelAnimationActivity.class), options);
-            mNeedsAnimationCancel = false;
-            return;
-        }
         mPaused = false;
 
         updateVrSupportLevel();
@@ -971,7 +956,6 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
         }
 
         if (mDonSucceeded) {
-            mCancellingEntryAnimation = false;
             handleDonFlowSuccess();
         } else if (mRestoreOrientation != null) {
             // This means the user backed out of the DON flow, and we won't be entering VR.
@@ -996,9 +980,8 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
     }
 
     private void onPause() {
-        mPaused = true;
-        if (mCancellingEntryAnimation) return;
         mExpectPauseOrDonSucceeded.removeCallbacksAndMessages(null);
+        mPaused = true;
         unregisterDaydreamIntent(mVrDaydreamApi);
         if (mVrSupportLevel == VR_NOT_AVAILABLE) return;
 
@@ -1020,18 +1003,8 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
         mIsDaydreamCurrentViewer = null;
     }
 
-    private void onStart() {
-        if (mDonSucceeded) {
-            // We're about to enter VR, so set the VR Mode as early as possible to avoid screen
-            // brightness flickering while in the headset.
-            mVrClassesWrapper.setVrModeEnabled(mActivity, true);
-            setWindowModeForVr(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
-        }
-    }
-
     private void onStop() {
         cancelPendingVrEntry();
-        assert !mCancellingEntryAnimation;
         // We defer pausing of VrShell until the app is stopped to keep head tracking working for
         // as long as possible while going to daydream home.
         if (mInVr) mVrShell.pause();
@@ -1140,8 +1113,6 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
         mEnterVrHandler.removeCallbacksAndMessages(null);
         mDonSucceeded = false;
         removeOverlayView();
-        mVrClassesWrapper.setVrModeEnabled(mActivity, false);
-        restoreWindowMode();
     }
 
     /**

chrome/android/java_sources.gni

@@ -1159,7 +1159,6 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/util/PlatformUtil.java",
   "java/src/org/chromium/chrome/browser/util/UrlUtilities.java",
   "java/src/org/chromium/chrome/browser/util/ViewUtils.java",
-  "java/src/org/chromium/chrome/browser/vr_shell/VrCancelAnimationActivity.java",
   "java/src/org/chromium/chrome/browser/vr_shell/NonPresentingGvrContext.java",
   "java/src/org/chromium/chrome/browser/vr_shell/VrClassesWrapper.java",
   "java/src/org/chromium/chrome/browser/vr_shell/VrCoreVersionChecker.java",