Apply automatic range checks to content enum types across IPC.

ui/gfx/font_render_params.h

Index: ui/gfx/font_render_params.h
diff --git a/ui/gfx/font_render_params.h b/ui/gfx/font_render_params.h
index ed4e593305696d847657e766dded8d2ec076487c..8febd661fd233edb3c8f2c11f80971511b460984 100644
--- a/ui/gfx/font_render_params.h
+++ b/ui/gfx/font_render_params.h
@@ -24,6 +24,8 @@ struct GFX_EXPORT FontRenderParams {
     HINTING_SLIGHT,
     HINTING_MEDIUM,
     HINTING_FULL,
+
+    HINTING_MAX = HINTING_FULL,
   };
 
   // Different subpixel orders to be used for subpixel rendering.
@@ -33,6 +35,8 @@ struct GFX_EXPORT FontRenderParams {
     SUBPIXEL_RENDERING_BGR,
     SUBPIXEL_RENDERING_VRGB,
     SUBPIXEL_RENDERING_VBGR,
+
+    SUBPIXEL_RENDERING_MAX = SUBPIXEL_RENDERING_VBGR,
   };
 
   // Antialiasing (grayscale if |subpixel_rendering| is SUBPIXEL_RENDERING_NONE