Remove the enable_metro GYP flag, effectively making it on by default.

ui/base/layout.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 "ui/base/layout.h"
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "build/build_config.h"
@@ skipping 23 matching lines @@
     if (switch_value.empty() ||
         switch_value == switches::kTouchOptimizedUIEnabled) {
       return true;
     } else if (switch_value == switches::kTouchOptimizedUIDisabled) {
       return false;
     } else if (switch_value != switches::kTouchOptimizedUIAuto) {
       LOG(ERROR) << "Invalid --touch-optimized-ui option: " << switch_value;
     }
   }
 
-#if defined(ENABLE_METRO)
+#if defined(OS_WIN)
+  // On Windows, we use the touch layout only when we are running in
+  // Metro mode.
   return base::win::GetMetroModule() != NULL;
-#elif defined(OS_WIN)
-  // No touch support on Win outside Metro yet (even with Aura).
-  return false;
 #elif defined(USE_AURA) && defined(USE_X11)
   // Determine whether touch-screen hardware is currently available.
   // For now we assume this won't change over the life of the process, but
   // we'll probably want to support that.  crbug.com/124399
   return ui::TouchFactory::GetInstance()->IsTouchDevicePresent();
 #else
   return false;
 #endif
 }
 
@@ skipping 18 matching lines @@
 #else
   return LAYOUT_DESKTOP;
 #endif
 }
 
 float GetScaleFactorScale(ScaleFactor scale_factor) {
   return kScaleFactorScales[scale_factor];
 }
 
 }  // namespace ui