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

content/shell/app/shell_main_delegate.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/shell/app/shell_main_delegate.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/path_service.h"
@@ skipping 94 matching lines @@
   InitLogging();
   CommandLine& command_line = *CommandLine::ForCurrentProcess();
   if (command_line.HasSwitch(switches::kCheckLayoutTestSysDeps)) {
     if (!CheckLayoutSystemDeps()) {
       if (exit_code)
         *exit_code = 1;
       return true;
     }
   }
   if (command_line.HasSwitch(switches::kDumpRenderTree)) {
+    EnableBrowserLayoutTestMode();
+
     command_line.AppendSwitch(switches::kProcessPerTab);
     command_line.AppendSwitch(switches::kAllowFileAccessFromFiles);
     command_line.AppendSwitchASCII(
         switches::kUseGL, gfx::kGLImplementationOSMesaName);
-    SetAllowOSMesaImageTransportForTesting();
-    DisableSystemDragDrop();
-    DisableModalPopupMenus();
     command_line.AppendSwitch(switches::kSkipGpuDataLoading);
     command_line.AppendSwitch(switches::kEnableExperimentalWebKitFeatures);
     command_line.AppendSwitch(switches::kEnableCssShaders);
     command_line.AppendSwitchASCII(switches::kTouchEvents,
                                    switches::kTouchEventsEnabled);
     command_line.AppendSwitch(switches::kEnableGestureTapHighlight);
     command_line.AppendSwitch(cc::switches::kDisableThreadedAnimation);
     if (command_line.HasSwitch(switches::kEnableSoftwareCompositing))
       command_line.AppendSwitch(switches::kEnableSoftwareCompositingGLAdapter);
 
@@ skipping 69 matching lines @@
   browser_client_.reset(new ShellContentBrowserClient);
   return browser_client_.get();
 }
 
 ContentRendererClient* ShellMainDelegate::CreateContentRendererClient() {
   renderer_client_.reset(new ShellContentRendererClient);
   return renderer_client_.get();
 }
 
 }  // namespace content