Attempt 3 at:

chrome/common/chrome_switches.cc

 // Copyright (c) 2011 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/common/chrome_switches.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 
 namespace switches {
@@ skipping 1268 matching lines @@
 // Disables print preview (Not exposed via about:flags. Only used for testing.)
 const char kDisablePrintPreview[]           = "disable-print-preview";
 
 // Enables print preview (no PDF viewer, thus not supported with Chromium).
 // kDisablePrintPreview overrides this.
 const char kEnablePrintPreview[]            = "enable-print-preview";
 
 // Enables the benchmarking extensions.
 const char kEnableBenchmarking[]            = "enable-benchmarking";
 
+#if defined(USE_AURA)
+// Forces usage of the test compositor. Needed to run ui tests on bots.
+extern const char kTestCompositor[]         = "test-compositor";
+#endif
+
 bool IsPrintPreviewEnabled() {
   if (CommandLine::ForCurrentProcess()->HasSwitch(kDisablePrintPreview))
     return false;
   return CommandLine::ForCurrentProcess()->HasSwitch(kEnablePrintPreview);
 }
 
 bool IsInBrowserThumbnailingEnabled() {
   return CommandLine::ForCurrentProcess()->HasSwitch(
       kEnableInBrowserThumbnailing);
 }
 
 // -----------------------------------------------------------------------------
 // DO NOT ADD YOUR CRAP TO THE BOTTOM OF THIS FILE.
 //
 // You were going to just dump your switches here, weren't you? Instead, please
 // put them in alphabetical order above, or in order inside the appropriate
 // ifdef at the bottom. The order should match the header.
 // -----------------------------------------------------------------------------
 
 }  // namespace switches