Fifth attempt to land faster rect blur.  Remove unnecessary conditionals from the shader.

approved over in https://codereview.chromium.org/331863006/; reuploading
because it had the wrong base url

BUG=skia:2095
R=bsalomon@google.com
TBR=bsalomon

Author: humper@google.com

Review URL: https://codereview.chromium.org/341543005
diff --git a/src/gpu/gl/GrGLShaderBuilder.cpp b/src/gpu/gl/GrGLShaderBuilder.cpp
index f8f810f..4b2778c 100644
--- a/src/gpu/gl/GrGLShaderBuilder.cpp
+++ b/src/gpu/gl/GrGLShaderBuilder.cpp
@@ -216,7 +216,7 @@
         if (GrGLProgramDesc::kSecondaryCoverageISA_CoverageOutput == header.fCoverageOutput) {
             // Get (1-A) into coeff
             coeff = GrGLSLExpr4::VectorCast(GrGLSLExpr1(1) - inputColor.a());
-        } else if (GrGLProgramDesc::kSecondaryCoverageISC_CoverageOutput == 
+        } else if (GrGLProgramDesc::kSecondaryCoverageISC_CoverageOutput ==
                    header.fCoverageOutput){
             // Get (1-RGBA) into coeff
             coeff = GrGLSLExpr4(1) - inputColor;