Add .0 on float GLSL literals to fix GLPrograms test break



git-svn-id: http://skia.googlecode.com/svn/trunk@4952 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/effects/GrConvolutionEffect.cpp b/src/gpu/effects/GrConvolutionEffect.cpp
index a28d44d..2d705fa 100644
--- a/src/gpu/effects/GrConvolutionEffect.cpp
+++ b/src/gpu/effects/GrConvolutionEffect.cpp
@@ -74,7 +74,7 @@
     const GrGLShaderVar& kernel = builder->getUniformVariable(fKernelUni);
     const char* imgInc = builder->getUniformCStr(fImageIncrementUni);
 
-    code->appendf("\t\tvec2 coord = %s - %d * %s;\n",
+    code->appendf("\t\tvec2 coord = %s - %d.0 * %s;\n",
                   builder->fSampleCoords.c_str(), fRadius, imgInc);
 
     // Manually unroll loop because some drivers don't; yields 20-30% speedup.