Correct location bar behavior on load fail

chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarManager.java

 // Copyright 2015 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.toolbar;
 
 import android.content.Context;
 import android.content.res.Configuration;
 import android.graphics.drawable.Drawable;
 import android.os.Handler;
@@ skipping 398 matching lines @@
                     ntp.setUrlFocusAnimationsDisabled(true);
                     mToolbar.onTabOrModelChanged();
                 }
             }
 
             @Override
             public void onDidFailLoad(Tab tab, boolean isProvisionalLoad, boolean isMainFrame,
                     int errorCode, String description, String failingUrl) {
                 NewTabPage ntp = mToolbarModel.getNewTabPageForCurrentTab();
                 if (ntp == null) return;
-                if (isProvisionalLoad && isMainFrame) {
+
+                // If the load failed due to a different navigation, there is no need to reset the
+                // the location bar animations.
+                boolean isFailingToNtp = tab.getWebContents() != null

[Ted C, 2016/08/02 20:55:18]

Hmm...I'm a bit confused what this is checking for.

Is the problem something like:

1.) You're on the NTP
2.) You tap a most visited item <foo.com>, navigation happens to foo.com
3.) You tap another most visited item, navigation in #2 is failed, new
navigation to foo.com is started

Wondering if #3 is right.

I'm wondering if the visible URL is the best indicator.  Or whether we should
look for a pending navigation.

isFailingToNtp also is a bit confusing to me/hard to grok.  My thinking about
pending navigations would be moving towards naming this hasPendingNavigation or
something as that is clearer where we wouldn't reset the state if there was a
pending navigation.  No idea if we can figure this out at this point though.

+                        && tab.getWebContents().getVisibleUrl().equals(UrlConstants.NTP_URL);
+
+                if (isProvisionalLoad && isMainFrame && isFailingToNtp) {
                     ntp.setUrlFocusAnimationsDisabled(false);
                     mToolbar.onTabOrModelChanged();
+                    if (mToolbar.getProgressBar() != null) mToolbar.getProgressBar().finish(false);
                 }
             }
 
             @Override
             public void onContextualActionBarVisibilityChanged(Tab tab, boolean visible) {
                 if (visible) RecordUserAction.record("MobileActionBarShown");
                 ActionBar actionBar = mActionBarDelegate.getSupportActionBar();
                 if (!visible && actionBar != null) actionBar.hide();
                 if (DeviceFormFactor.isTablet(activity)) {
                     if (visible) {
@@ skipping 784 matching lines @@
         }
 
         /**
          * Cancels simulating load progress.
          */
         public void cancel() {
             mHandler.removeMessages(MSG_ID_UPDATE_PROGRESS);
         }
     }
 }