Add flag which shows missing 2x resources

ui/base/ui_base_switches.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/ui_base_switches.h"
 
 namespace switches {
 
 // The default device scale factor to apply to the browser UI and
 // the contents in the absence of a viewport meta tag.
 const char kDefaultDeviceScaleFactor[] = "default-device-scale-factor";
 
 // Let text glyphs have X-positions that aren't snapped to the pixel grid.
 const char kEnableTextSubpixelPositioning[] =
     "enable-text-subpixel-positioning";
 
 // Enable touch screen calibration.
 const char kEnableTouchCalibration[] = "enable-touch-calibration";
 
 // Enable support for touch events.
 const char kEnableTouchEvents[] = "enable-touch-events";
 
+// Generates a 2x version of resources for which no 2x version is available or
+// the 2x version is of an incorrect size and applies a red mask to the
+// resource. Resources for which hidpi is not supported because of software
+// reasons will show up pixelated.
+const char kHighlightMissing2xResources[] =
+    "highlight-missing-2x-resources";
+
 // The language file that we want to try to open. Of the form
 // language[-country] where language is the 2 letter code from ISO-639.
 const char kLang[] = "lang";
 
 // Loads 2x resources. These resource paks currently contain
 // mix of 1x and 2x and loading them may break the UI on 2x display.
 const char kLoad2xResources[] = "load-2x-resources";
 
 // Load the locale resources from the given path. When running on Mac/Unix the
 // path should point to a locale.pak file.
@@ skipping 23 matching lines @@
 #endif
 
 #if defined(TOOLKIT_VIEWS) && defined(OS_LINUX)
 // Tells chrome to interpret events from these devices as touch events. Only
 // available with XInput 2 (i.e. X server 1.8 or above). The id's of the
 // devices can be retrieved from 'xinput list'.
 const char kTouchDevices[] = "touch-devices";
 #endif
 
 }  // namespace switches