Disable GL_MULTISAMPLE when it's not being used

src/gpu/GrPipelineBuilder.cpp

Index: src/gpu/GrPipelineBuilder.cpp
diff --git a/src/gpu/GrPipelineBuilder.cpp b/src/gpu/GrPipelineBuilder.cpp
index b3b602f4690de89ace53c4be2949cf30fe839553..1d8aa4f2b4f9baa9b21496272dfac6b7f04c85f7 100644
--- a/src/gpu/GrPipelineBuilder.cpp
+++ b/src/gpu/GrPipelineBuilder.cpp
@@ -74,7 +74,8 @@ void GrPipelineBuilder::setFromPaint(const GrPaint& paint, GrRenderTarget* rt, c
     fClip = clip;
 
     this->setState(GrPipelineBuilder::kDither_StateBit, paint.isDither());
-    this->setState(GrPipelineBuilder::kHWAntialias_StateBit, paint.isAntiAlias());
+    this->setState(GrPipelineBuilder::kHWAntialias_StateBit,
+                   rt->isMultisampled() && paint.isAntiAlias());
 
     fColorProcInfoValid = false;
     fCoverageProcInfoValid = false;