Create GLSLUniformHandler class for gpu backend

BUG=skia:

Review URL: https://codereview.chromium.org/1490283004
diff --git a/src/effects/SkMorphologyImageFilter.cpp b/src/effects/SkMorphologyImageFilter.cpp
index 484ed57..c6bbce7 100644
--- a/src/effects/SkMorphologyImageFilter.cpp
+++ b/src/effects/SkMorphologyImageFilter.cpp
@@ -21,8 +21,8 @@
 #include "effects/Gr1DKernelEffect.h"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
-#include "glsl/GrGLSLProgramBuilder.h"
 #include "glsl/GrGLSLProgramDataManager.h"
+#include "glsl/GrGLSLUniformHandler.h"
 #endif
 
 SkMorphologyImageFilter::SkMorphologyImageFilter(int radiusX,
@@ -288,14 +288,15 @@
 }
 
 void GrGLMorphologyEffect::emitCode(EmitArgs& args) {
-    fPixelSizeUni = args.fBuilder->addUniform(GrGLSLProgramBuilder::kFragment_Visibility,
-                                            kFloat_GrSLType, kDefault_GrSLPrecision,
-                                            "PixelSize");
-    const char* pixelSizeInc = args.fBuilder->getUniformCStr(fPixelSizeUni);
-    fRangeUni = args.fBuilder->addUniform(GrGLSLProgramBuilder::kFragment_Visibility,
-                                            kVec2f_GrSLType, kDefault_GrSLPrecision,
-                                            "Range");
-    const char* range = args.fBuilder->getUniformCStr(fRangeUni);
+    GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
+    fPixelSizeUni = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
+                                               kFloat_GrSLType, kDefault_GrSLPrecision,
+                                               "PixelSize");
+    const char* pixelSizeInc = uniformHandler->getUniformCStr(fPixelSizeUni);
+    fRangeUni = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
+                                           kVec2f_GrSLType, kDefault_GrSLPrecision,
+                                           "Range");
+    const char* range = uniformHandler->getUniformCStr(fRangeUni);
 
     GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
     SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 0);