Reset tab-icon animations for loading -> waiting

Prevents showing earlier favicon from the earlier page load that did not
finish (was still at loading). Also allows the favicon of the new page
load to fade in.

Bug: chromium:907642, chromium:910848
Change-Id: I65fb44b7f432d5a0f4cd484f5a497f9b8a327c62
Reviewed-on: https://chromium-review.googlesource.com/c/1361282
Reviewed-by: Sidney San Martín <sdy@chromium.org>
Commit-Queue: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613631}

chrome/browser/ui/views/tabs/tab_icon.cc

@@ -475,8 +475,10 @@ void TabIcon::SetNetworkState(TabNetworkState network_state,
     bool was_animated = NetworkStateIsAnimated(old_state);
     bool is_animated = NetworkStateIsAnimated(network_state_);
 
-    if (!was_animated && is_animated) {
-      // Reset all animations.
+    // If we either start animating (or from loading to waiting), reset all
+    // animations.
+    if ((!was_animated && is_animated) ||
+        network_state_ == TabNetworkState::kWaiting) {
       last_animation_update_time_ = clock_->NowTicks();
       pending_animation_state_ = LoadingAnimationState();
       pending_animation_state_.favicon_fade_in_progress.reset();