Log the expected icon size when no suitable icon for a banner is found.

chrome/browser/banners/app_banner_debug_log.cc

 // 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.
 
 #include "chrome/browser/banners/app_banner_debug_log.h"
 
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 
 namespace banners {
 
 const char kRendererRequestCancel[] =
     "renderer has requested the banner prompt be cancelled";
 const char kManifestEmpty[] =
     "manifest could not be fetched, is empty, or could not be parsed";
 const char kNoManifest[] = "site has no manifest <link> URL";
-const char kCannotDetermineBestIcon[] =
-    "could not determine the best icon to use";
+// The required size is prepended.
+const char kNoIconMatchingRequirements[] =
+    "px square icon is required, but no supplied icon is at least this size";
+const char kCannotDownloadIcon[] = "could not download the specified icon";
 const char kNoMatchingServiceWorker[] =
     "no matching service worker detected. You may need to reload the page, or "
     "check that the service worker for the current page also controls the "
     "start URL from the manifest";
 const char kNoIconAvailable[] = "no icon available to display";
 const char kUserNavigatedBeforeBannerShown[] =
     "the user navigated before the banner could be shown";
 const char kStartURLNotValid[] = "start URL in manifest is not valid";
 const char kManifestMissingNameOrShortName[] =
     "one of manifest name or short name must be specified";
@@ skipping 21 matching lines @@
 void OutputDeveloperDebugMessage(content::WebContents* web_contents,
                                  const std::string& message,
                                  bool is_debug_mode) {
   if (!is_debug_mode || !web_contents)
     return;
   web_contents->GetMainFrame()->AddMessageToConsole(
       content::CONSOLE_MESSAGE_LEVEL_DEBUG, "App banner " + message);
 }
 
 }  // namespace banners