Add support for IMG's MSAA extension.

src/gpu/gl/GrGLCaps.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef GrGLCaps_DEFINED
 #define GrGLCaps_DEFINED
@@ skipping 44 matching lines @@
          */
         kDesktopARB_MSFBOType,
         /**
          * earlier GL_EXT_framebuffer* extensions
          */
         kDesktopEXT_MSFBOType,
         /**
          * GL_APPLE_framebuffer_multisample ES extension
          */
         kAppleES_MSFBOType,
+        /**
+         * GL_IMG_multisampled_render_to_texture
+         */
+        kImaginationES_MSFBOType,
     };
 
     enum CoverageAAType {
         /**
          * No coverage sample support
          */
         kNone_CoverageAAType,
 
         /**
          * GL_NV_framebuffer_multisample_coverage
@@ skipping 225 matching lines @@
     bool fTextureRedSupport : 1;
     bool fImagingSupport  : 1;
     bool fTwoFormatLimit : 1;
     bool fFragCoordsConventionSupport : 1;
     bool fVertexArrayObjectSupport : 1;
     bool fUseNonVBOVertexAndIndexDynamicData : 1;
     bool fIsCoreProfile : 1;
 };
 
 #endif