Introduce the notion of a "layout test mode" instead of turning individual flags on and off

content/renderer/renderer_webapplicationcachehost_impl.cc

 // Copyright (c) 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.
 
 #include "content/renderer/renderer_webapplicationcachehost_impl.h"
 
 #include "content/common/view_messages.h"
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/render_view_impl.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
 
 using appcache::AppCacheBackend;
 using WebKit::WebApplicationCacheHostClient;
 using WebKit::WebConsoleMessage;
 
 namespace content {
 
-static bool g_disable_logging = false;
-
 RendererWebApplicationCacheHostImpl::RendererWebApplicationCacheHostImpl(
     RenderViewImpl* render_view,
     WebApplicationCacheHostClient* client,
     AppCacheBackend* backend)
     : WebApplicationCacheHostImpl(client, backend),
       routing_id_(render_view->routing_id()) {
 }
 
 void RendererWebApplicationCacheHostImpl::OnLogMessage(
     appcache::LogLevel log_level, const std::string& message) {
-  if (g_disable_logging)
+  if (RenderThreadImpl::current()->layout_test_mode())
     return;
 
   RenderViewImpl* render_view = GetRenderView();
   if (!render_view || !render_view->webview() ||
       !render_view->webview()->mainFrame())
     return;
 
   WebKit::WebFrame* frame = render_view->webview()->mainFrame();
   frame->addMessageToConsole(WebConsoleMessage(
         static_cast<WebConsoleMessage::Level>(log_level),
@@ skipping 12 matching lines @@
     RenderThreadImpl::current()->Send(new ViewHostMsg_AppCacheAccessed(
         routing_id_, info.manifest_url, false));
   }
   WebApplicationCacheHostImpl::OnCacheSelected(info);
 }
 
 RenderViewImpl* RendererWebApplicationCacheHostImpl::GetRenderView() {
   return RenderViewImpl::FromRoutingID(routing_id_);
 }
 
-// static
-void RendererWebApplicationCacheHostImpl::DisableLoggingForTesting() {
-  g_disable_logging = true;
-}
-
 }  // namespace content