Make it possible to toggle MSAA for ES (EXT_multisample_compatibility)

src/gpu/gl/GrGLCaps.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLCaps.h"
 
@@ skipping 250 matching lines @@
     if (kGL_GrGLStandard == standard) {
         fES2CompatibilitySupport = ctxInfo.hasExtension("GL_ARB_ES2_compatibility");
     }
     else {
         fES2CompatibilitySupport = true;
     }
 
     if (kGL_GrGLStandard == standard) {
         fMultisampleDisableSupport = true;
     } else {
-        fMultisampleDisableSupport = false;
+        fMultisampleDisableSupport = ctxInfo.hasExtension("GL_EXT_multisample_compatibility");
     }
 
     if (kGL_GrGLStandard == standard && version >= GR_GL_VER(3, 0)) {
         fBindFragDataLocationSupport = true;
     }
 
     /**************************************************************************
     * GrShaderCaps fields
     **************************************************************************/
 
@@ skipping 919 matching lines @@
         for (int p = 0; p < kGrSLPrecisionCount; ++p) {
             glslCaps->fFloatPrecisions[kGeometry_GrShaderType][p] = 
                                                glslCaps->fFloatPrecisions[kVertex_GrShaderType][p];
         }
     }
 }