[Mac][Material Design] Fix SelectedKeywordDecoration tests for MD.

chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.mm

 // Copyright 2012 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.
 
 #import "chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #import "base/mac/mac_util.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 441 matching lines @@
     short_name = TemplateURLServiceFactory::GetForProfile(profile())->
         GetKeywordShortName(keyword, &is_extension_keyword);
   }
 
   const bool is_keyword_hint = omnibox_view_->model()->is_keyword_hint();
   if (!keyword.empty() && !is_keyword_hint) {
     // Switch from location icon to keyword mode.
     location_icon_decoration_->SetVisible(false);
     selected_keyword_decoration_->SetVisible(true);
     selected_keyword_decoration_->SetKeyword(short_name, is_extension_keyword);
+    // Note: the first time through this code path the
+    // |selected_keyword_decoration_| has no image set because under Material
+    // Design we need to set its color, which we cannot do until we know the
+    // theme (by being installed in a browser window).
     selected_keyword_decoration_->SetImage(GetKeywordImage(keyword));
   } else if (ShouldShowEVBubble()) {
     // Switch from location icon to show the EV bubble instead.
     location_icon_decoration_->SetVisible(false);
     ev_bubble_decoration_->SetVisible(true);
 
     base::string16 label(GetToolbarModel()->GetEVCertName());
     ev_bubble_decoration_->SetFullLabel(base::SysUTF16ToNSString(label));
   } else if (!keyword.empty() && is_keyword_hint) {
     keyword_hint_decoration_->SetKeyword(short_name,
@@ skipping 333 matching lines @@
   return zoom_decoration_->UpdateIfNecessary(
       ui_zoom::ZoomController::FromWebContents(web_contents),
       default_zoom_changed,
       in_dark_mode);
 }
 
 void LocationBarViewMac::OnDefaultZoomLevelChanged() {
   if (UpdateZoomDecoration(/*default_zoom_changed=*/true))
     OnDecorationsChanged();
 }