Apply automatic range checks to content enum types across IPC.

ui/gfx/font_render_params.h

 // Copyright 2014 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.
 
 #ifndef UI_GFX_FONT_RENDER_PARAMS_H_
 #define UI_GFX_FONT_RENDER_PARAMS_H_
 
 #include <string>
 #include <vector>
 
 #include "third_party/skia/include/core/SkFontHost.h"
 #include "ui/gfx/gfx_export.h"
 
 namespace gfx {
 
 // A collection of parameters describing how text should be rendered on Linux.
 struct GFX_EXPORT FontRenderParams {
   FontRenderParams();
   ~FontRenderParams();
 
   // Level of hinting to be applied.
   enum Hinting {
     HINTING_NONE = 0,
     HINTING_SLIGHT,
     HINTING_MEDIUM,
     HINTING_FULL,
+
+    HINTING_MAX = HINTING_FULL,
   };
 
   // Different subpixel orders to be used for subpixel rendering.
   enum SubpixelRendering {
     SUBPIXEL_RENDERING_NONE = 0,
     SUBPIXEL_RENDERING_RGB,
     SUBPIXEL_RENDERING_BGR,
     SUBPIXEL_RENDERING_VRGB,
     SUBPIXEL_RENDERING_VBGR,
+
+    SUBPIXEL_RENDERING_MAX = SUBPIXEL_RENDERING_VBGR,
   };
 
   // Antialiasing (grayscale if |subpixel_rendering| is SUBPIXEL_RENDERING_NONE
   // and RGBA otherwise).
   bool antialiasing;
 
   // Should subpixel positioning (i.e. fractional X positions for glyphs) be
   // used?
   // TODO(derat): Remove this; we don't set it in the browser and mostly ignore
   // it in Blink: http://crbug.com/396659
@@ skipping 62 matching lines @@
 
 // Sets the device scale factor for FontRenderParams to decide
 // if it should enable subpixel positioning.
 GFX_EXPORT void SetFontRenderParamsDeviceScaleFactor(
     float device_scale_factor);
 #endif
 
 }  // namespace gfx
 
 #endif  // UI_GFX_FONT_RENDER_PARAMS_H_