Remove redundant auto rt object in skpaint2grpaintshader function.

R=robertphillips@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/133763006

git-svn-id: http://skia.googlecode.com/svn/trunk@13046 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index c997b79..39f9ef3 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -506,10 +506,9 @@
         return skPaint2GrPaintNoShader(dev, skPaint, false, constantColor, grPaint);
     }
 
-    // SkShader::asNewEffect() may do offscreen rendering. Setup default drawing state
-    // Also require shader to set the render target .
+    // SkShader::asNewEffect() may do offscreen rendering. Setup default drawing state and require
+    // the shader to set a render target .
     GrContext::AutoWideOpenIdentityDraw awo(dev->context(), NULL);
-    GrContext::AutoRenderTarget(dev->context(), NULL);
 
     // setup the shader as the first color effect on the paint
     SkAutoTUnref<GrEffectRef> effect(shader->asNewEffect(dev->context(), skPaint));