Use a pseudo-extension CHROMIUM_framebuffer_mixed_samples

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 302 matching lines @@
             ctxInfo.hasExtension("GL_OES_standard_derivatives");
     }
 
     /**************************************************************************
      * GrCaps fields
      **************************************************************************/
 
     // We need dual source blending and the ability to disable multisample in order to support mixed
     // samples in every corner case.
     if (fMultisampleDisableSupport && glslCaps->dualSourceBlendingSupport()) {
-        fMixedSamplesSupport = ctxInfo.hasExtension("GL_NV_framebuffer_mixed_samples");
+        fMixedSamplesSupport = ctxInfo.hasExtension("GL_NV_framebuffer_mixed_samples") ||
+                ctxInfo.hasExtension("GL_CHROMIUM_framebuffer_mixed_samples");
         // Workaround NVIDIA bug related to glInvalidateFramebuffer and mixed samples.
         if (fMixedSamplesSupport && kNVIDIA_GrGLDriver == ctxInfo.driver()) {
             fDiscardRenderTargetSupport = false;
             fInvalidateFBType = kNone_InvalidateFBType;
         }
     }
 
     // fPathRenderingSupport and fMixedSamplesSupport must be set before calling initFSAASupport.
     this->initFSAASupport(ctxInfo, gli);
     this->initBlendEqationSupport(ctxInfo);
@@ skipping 1013 matching lines @@
     glslCaps->fConfigSwizzle[kR11_EAC_GrPixelConfig] = "rrrr";
     glslCaps->fConfigSwizzle[kASTC_12x12_GrPixelConfig] = "rgba";
     glslCaps->fConfigSwizzle[kRGBA_float_GrPixelConfig] = "rgba";
     glslCaps->fConfigSwizzle[kRGBA_half_GrPixelConfig] = "rgba";
 
 }
 
 void GrGLCaps::onApplyOptionsOverrides(const GrContextOptions& options) {}