one channel texture fix for blur shader

BUG=skia:
R=bsalomon@google.com
TBR=bsalomon
NOTRY=True
NOTREECHECKS=True

Author: humper@google.com

Review URL: https://codereview.chromium.org/319543007

diff --git a/src/effects/SkBlurMaskFilter.cpp b/src/effects/SkBlurMaskFilter.cpp
index f976048..80fa9f8 100644 (file)
--- a/src/effects/SkBlurMaskFilter.cpp
+++ b/src/effects/SkBlurMaskFilter.cpp
@@ -634,7 +634,7 @@ void OutputRectBlurProfileLookup(GrGLShaderBuilder* builder,
                            loc, blurred_width, sharp_width, profileSize);
     builder->fsCodeAppendf("\t\t%s = ", output);
     builder->fsAppendTextureLookup(sampler, "vec2(coord,0.5)");
-    builder->fsCodeAppend(";\n");
+    builder->fsCodeAppend(".a;\n");
 }
 
 void GrGLRectBlurEffect::emitCode(GrGLShaderBuilder* builder,