When wrapping external textures, clamp the MSAA sample count to max.

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 "GrGLStencilBuffer.h"
@@ skipping 383 matching lines @@
     GrSurfaceDesc surfDesc;
 
     idDesc.fTextureID = static_cast<GrGLuint>(desc.fTextureHandle);
     idDesc.fLifeCycle = GrGpuResource::kWrapped_LifeCycle;
 
     // next line relies on GrBackendTextureDesc's flags matching GrTexture's
     surfDesc.fFlags = (GrSurfaceFlags) desc.fFlags;
     surfDesc.fWidth = desc.fWidth;
     surfDesc.fHeight = desc.fHeight;
     surfDesc.fConfig = desc.fConfig;
-    surfDesc.fSampleCnt = desc.fSampleCnt;
+    surfDesc.fSampleCnt = SkTMin(desc.fSampleCnt, this->caps()->maxSampleCount());
     bool renderTarget = SkToBool(desc.fFlags & kRenderTarget_GrBackendTextureFlag);
     // FIXME:  this should be calling resolve_origin(), but Chrome code is currently
     // assuming the old behaviour, which is that backend textures are always
     // BottomLeft, even for non-RT's.  Once Chrome is fixed, change this to:
     // glTexDesc.fOrigin = resolve_origin(desc.fOrigin, renderTarget);
     if (kDefault_GrSurfaceOrigin == desc.fOrigin) {
         surfDesc.fOrigin = kBottomLeft_GrSurfaceOrigin;
     } else {
         surfDesc.fOrigin = desc.fOrigin;
     }
@@ skipping 20 matching lines @@
     idDesc.fRTFBOID = static_cast<GrGLuint>(wrapDesc.fRenderTargetHandle);
     idDesc.fMSColorRenderbufferID = 0;
     idDesc.fTexFBOID = GrGLRenderTarget::kUnresolvableFBOID;
     idDesc.fLifeCycle = GrGpuResource::kWrapped_LifeCycle;
 
     GrSurfaceDesc desc;
     desc.fConfig = wrapDesc.fConfig;
     desc.fFlags = kCheckAllocation_GrSurfaceFlag;
     desc.fWidth = wrapDesc.fWidth;
     desc.fHeight = wrapDesc.fHeight;
-    desc.fSampleCnt = wrapDesc.fSampleCnt;
+    desc.fSampleCnt = SkTMin(wrapDesc.fSampleCnt, this->caps()->maxSampleCount());
     desc.fOrigin = resolve_origin(wrapDesc.fOrigin, true);
 
     GrRenderTarget* tgt = SkNEW_ARGS(GrGLRenderTarget, (this, desc, idDesc));
     if (wrapDesc.fStencilBits) {
         GrGLStencilBuffer::IDDesc sbDesc;
         GrGLStencilBuffer::Format format;
         format.fInternalFormat = GrGLStencilBuffer::kUnknownInternalFormat;
         format.fPacked = false;
         format.fStencilBits = wrapDesc.fStencilBits;
         format.fTotalBits = wrapDesc.fStencilBits;
@@ skipping 2360 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }