Fix smooth progress behavior on JellyBean

chrome/android/java/src/org/chromium/chrome/browser/widget/ToolbarProgressBarAnimatingView.java

 // Copyright 2016 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.widget;
 
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.animation.AnimatorSet;
 import android.animation.ValueAnimator;
@@ skipping 43 matching lines @@
     /** If the layout is RTL. */
     private boolean mIsRtl;
 
     /** The update listener for the animation. */
     private ProgressBarUpdateListener mListener;
 
     /** The last fraction of the animation that was drawn. */
     private float mLastAnimatedFraction;
 
     /**
+     * If the animation is currently running. This is needed because Animator.isStarted() is not
+     * reliable on JellyBean.
+     */
+    private boolean mIsAnimationRunning;
+
+    /**
      * An animation update listener that moves an ImageView across the progress bar.
      */
     private class ProgressBarUpdateListener implements AnimatorUpdateListener {
         @Override
         public void onAnimationUpdate(ValueAnimator animation) {
             mLastAnimatedFraction = animation.getAnimatedFraction();
             updateAnimation(mLastAnimatedFraction);
         }
     }
 
     /**
      * @param context The Context for this view.
      * @param height The LayoutParams for this view.
      */
     public ToolbarProgressBarAnimatingView(Context context, LayoutParams layoutParams) {
         super(context);
-
         setLayoutParams(layoutParams);
         mIsRtl = LocalizationUtils.isLayoutRtl();
 
         mAnimationDrawable = new ColorDrawable(Color.WHITE);
 
         setImageDrawable(mAnimationDrawable);
 
         mListener = new ProgressBarUpdateListener();
         mAnimatorSet = new AnimatorSet();
 
@@ skipping 19 matching lines @@
                 mAnimatorSet.start();
             }
         });
     }
 
     /**
      * Start the animation if it hasn't been already.
      */
     public void startAnimation() {
         mIsCanceled = false;
-        if (!mAnimatorSet.isStarted()) {
+        if (!mIsAnimationRunning) {
+            mIsAnimationRunning = true;
             // Set the initial start delay to 0ms so it starts immediately.
             mAnimatorSet.setStartDelay(0);
 
             // Reset position.
             setScaleX(0.0f);
             setTranslationX(0.0f);
             mAnimatorSet.start();
 
             // Fade in to look nice on sites that trigger many loads that end quickly.
             animate().alpha(1.0f)
@@ skipping 42 matching lines @@
      */
     public boolean isRunning() {
         return mAnimatorSet.isStarted();
     }
 
     /**
      * Cancel the animation.
      */
     public void cancelAnimation() {
         mIsCanceled = true;
-        mAnimatorSet.cancel();
+        mIsAnimationRunning = false;
         // Reset position and alpha.
         setScaleX(0.0f);
         setTranslationX(0.0f);
         animate().cancel();
         setAlpha(0.0f);
         mLastAnimatedFraction = 0.0f;
     }
 
     /**
      * Update info about the progress bar holding this animating block.
      * @param progressWidth The width of the contaiing progress bar.
      */
     public void update(float progressWidth) {
         mProgressWidth = progressWidth;
         updateAnimation(mLastAnimatedFraction);
     }
 
     /**
      * @param color The Android color that the animating bar should be.
      */
     public void setColor(int color) {
         mAnimationDrawable.setColor(color);
     }
 }