Add Gr*Proxy classes

src/gpu/gl/GrGLGpu.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLGpu.h"
 #include "GrGLBuffer.h"
 #include "GrGLGLSL.h"
@@ skipping 1467 matching lines @@
     return (GR_GL_NO_ERROR == CHECK_ALLOC_ERROR(ctx.interface()));
 }
 
 bool GrGLGpu::createRenderTargetObjects(const GrSurfaceDesc& desc,
                                         const GrGLTextureInfo& texInfo,
                                         GrGLRenderTarget::IDDesc* idDesc) {
     idDesc->fMSColorRenderbufferID = 0;
     idDesc->fRTFBOID = 0;
     idDesc->fRTFBOOwnership = GrBackendObjectOwnership::kOwned;
     idDesc->fTexFBOID = 0;
-    idDesc->fSampleConfig = (GrGLCaps::kMixedSamples_MSFBOType == this->glCaps().msFBOType() &&
-                            desc.fSampleCnt > 0) ? GrRenderTarget::kStencil_SampleConfig :
-                                                   GrRenderTarget::kUnified_SampleConfig;
+    SkASSERT((GrGLCaps::kMixedSamples_MSFBOType == this->glCaps().msFBOType()) ==
+             this->caps()->usesMixedSamples());
+    idDesc->fSampleConfig = GrRenderTarget::ComputeSampleConfig(*this->caps(), desc.fSampleCnt);
 
     GrGLenum status;
 
     GrGLenum colorRenderbufferFormat = 0; // suppress warning
 
     if (desc.fSampleCnt > 0 && GrGLCaps::kNone_MSFBOType == this->glCaps().msFBOType()) {
         goto FAILED;
     }
 
     GL_CALL(GenFramebuffers(1, &idDesc->fTexFBOID));
@@ skipping 2769 matching lines @@
         if (GR_GL_TEXTURE_EXTERNAL == glTexture->target() ||
             GR_GL_TEXTURE_RECTANGLE == glTexture->target()) {
             copyParams->fFilter = GrTextureParams::kNone_FilterMode;
             copyParams->fWidth = texture->width();
             copyParams->fHeight = texture->height();
             return true;
         }
     }
     return false;
 }