Views: Do not animate HTTP_SHOW_WARNING to DANGEROUS transition

This transition (which is currently only possible with an experiment enabled)
can look messy/confusing when animated, so do not animate it.

Bug: 807075
Change-Id: Ib7bda303958739cd4840dbc57910c1c850c5e97a
Reviewed-on: https://chromium-review.googlesource.com/891630Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Emily Stark <estark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533312}

chrome/browser/ui/views/location_bar/location_bar_view.cc

@@ -618,6 +618,7 @@ void LocationBarView::Update(const WebContents* contents) {
       ShouldShowLocationIconText(),
       !contents && ShouldAnimateLocationIconTextVisibilityChange());
   OnChanged();  // NOTE: Calls Layout().
+  last_update_security_level_ = GetToolbarModel()->GetSecurityLevel(false);
 }
 
 void LocationBarView::ResetTabState(WebContents* contents) {
@@ -877,10 +878,13 @@ bool LocationBarView::ShouldShowLocationIconText() const {
 }
 
 bool LocationBarView::ShouldAnimateLocationIconTextVisibilityChange() const {
-  // Text for extension URLs should not be animated (their security level is
-  // SecurityLevel::NONE).
   using SecurityLevel = security_state::SecurityLevel;
   SecurityLevel level = GetToolbarModel()->GetSecurityLevel(false);
+  // Do not animate transitions from HTTP_SHOW_WARNING to DANGEROUS, since the
+  // transition can look confusing/messy.
+  if (level == SecurityLevel::DANGEROUS &&
+      last_update_security_level_ == SecurityLevel::HTTP_SHOW_WARNING)
+    return false;
   return level == SecurityLevel::DANGEROUS ||
          level == SecurityLevel::HTTP_SHOW_WARNING;
 }

chrome/browser/ui/views/location_bar/location_bar_view.h

@@ -437,6 +437,11 @@ class LocationBarView : public LocationBar,
   // A list of all bubble descendants ordered by focus.
   std::vector<BubbleIconView*> bubble_icons_;
 
+  // The security level when the location bar was last updated. Used to decide
+  // whether to animate security level transitions.
+  security_state::SecurityLevel last_update_security_level_ =
+      security_state::NONE;
+
   DISALLOW_COPY_AND_ASSIGN(LocationBarView);
 };