fix undefined signed shifts

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 "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLProgramDataManager.h"
@@ skipping 96 matching lines @@
     SkString modulate;
     GrGLSLMulVarBy4f(&modulate, args.fOutputColor, args.fInputColor);
     fragBuilder->codeAppend(modulate.c_str());
 }
 
 void GrGLMatrixConvolutionEffect::GenKey(const GrProcessor& processor,
                                          const GrGLSLCaps&, GrProcessorKeyBuilder* b) {
     const GrMatrixConvolutionEffect& m = processor.cast<GrMatrixConvolutionEffect>();
     SkASSERT(m.kernelSize().width() <= 0x7FFF && m.kernelSize().height() <= 0xFFFF);
     uint32_t key = m.kernelSize().width() << 16 | m.kernelSize().height();
-    key |= m.convolveAlpha() ? 1 << 31 : 0;
+    key |= m.convolveAlpha() ? 1U << 31 : 0;
     b->add32(key);
     b->add32(GrTextureDomain::GLDomain::DomainKey(m.domain()));
 }
 
 void GrGLMatrixConvolutionEffect::onSetData(const GrGLSLProgramDataManager& pdman,
                                             const GrProcessor& processor) {
     const GrMatrixConvolutionEffect& conv = processor.cast<GrMatrixConvolutionEffect>();
     GrTexture& texture = *conv.texture(0);
 
     float imageIncrement[2];
@@ skipping 120 matching lines @@
     return GrMatrixConvolutionEffect::Create(d->fTextures[texIdx],
                                              bounds,
                                              kernelSize,
                                              kernel.get(),
                                              gain,
                                              bias,
                                              kernelOffset,
                                              tileMode,
                                              convolveAlpha);
 }