Fix GLSL error on Android.

src/gpu/effects/GrMatrixConvolutionEffect.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "GrMatrixConvolutionEffect.h"
 #include "gl/GrGLProcessor.h"
 #include "gl/GrGLSL.h"
 #include "gl/GrGLTexture.h"
@@ skipping 72 matching lines @@
 
     for (int y = 0; y < kHeight; y++) {
         for (int x = 0; x < kWidth; x++) {
             GrGLShaderBuilder::ShaderBlock block(fsBuilder);
             fsBuilder->codeAppendf("float k = %s[%d * %d + %d];", kernel, y, kWidth, x);
             SkString coord;
             coord.printf("coord + vec2(%d, %d) * %s", x, y, imgInc);
             fDomain.sampleTexture(fsBuilder, domain, "c", coord, samplers[0]);
             if (!fConvolveAlpha) {
                 fsBuilder->codeAppend("c.rgb /= c.a;");
-                fsBuilder->codeAppend("c.rgb = clamp(c.rgb, 0, 1);");
+                fsBuilder->codeAppend("c.rgb = clamp(c.rgb, 0.0, 1.0);");
             }
             fsBuilder->codeAppend("sum += c * k;");
         }
     }
     if (fConvolveAlpha) {
         fsBuilder->codeAppendf("%s = sum * %s + %s;", outputColor, gain, bias);
         fsBuilder->codeAppendf("%s.rgb = clamp(%s.rgb, 0.0, %s.a);",
                                outputColor, outputColor, outputColor);
     } else {
         fDomain.sampleTexture(fsBuilder, domain, "c", coords2D, samplers[0]);
@@ skipping 159 matching lines @@
     return GrMatrixConvolutionEffect::Create(textures[texIdx],
                                              bounds,
                                              kernelSize,
                                              kernel.get(),
                                              gain,
                                              bias,
                                              kernelOffset,
                                              tileMode,
                                              convolveAlpha);
 }