Refactor how we store and use samplers in Ganesh

src/gpu/gl/GrGLUniformHandler.cpp

Index: src/gpu/gl/GrGLUniformHandler.cpp
diff --git a/src/gpu/gl/GrGLUniformHandler.cpp b/src/gpu/gl/GrGLUniformHandler.cpp
index 94da1f177686b535e3a2a1a27262a46ef6a48089..98b4fb7bd5c2c2b5223915b80de62fbba5a4c68d 100644
--- a/src/gpu/gl/GrGLUniformHandler.cpp
+++ b/src/gpu/gl/GrGLUniformHandler.cpp
@@ -52,6 +52,22 @@ GrGLSLUniformHandler::UniformHandle GrGLUniformHandler::internalAddUniformArray(
     return GrGLSLUniformHandler::UniformHandle(fUniforms.count() - 1);
 }
 
+GrGLSLUniformHandler::SamplerHandle GrGLUniformHandler::internalAddSampler(uint32_t visibility,
+                                                                           GrPixelConfig config,
+                                                                           GrSLType type,
+                                                                           GrSLPrecision precision,
+                                                                           const char* name) {
+    SkASSERT(name && strlen(name));
+    SkDEBUGCODE(static const uint32_t kVisMask = kVertex_GrShaderFlag | kFragment_GrShaderFlag);
+    SkASSERT(0 == (~kVisMask & visibility));
+    SkASSERT(0 != visibility);
+    SkString mangleName;
+    char prefix = 'u';
+    fProgramBuilder->nameVariable(&mangleName, prefix, name, true);
+    fSamplers.emplace_back(visibility, config, type, precision, mangleName.c_str());
+    return GrGLSLUniformHandler::SamplerHandle(fSamplers.count() - 1);
+}
+
 void GrGLUniformHandler::appendUniformDecls(GrShaderFlags visibility, SkString* out) const {
     for (int i = 0; i < fUniforms.count(); ++i) {
         if (fUniforms[i].fVisibility & visibility) {
@@ -59,6 +75,12 @@ void GrGLUniformHandler::appendUniformDecls(GrShaderFlags visibility, SkString*
             out->append(";\n");
         }
     }
+    for (int i = 0; i < fSamplers.count(); ++i) {
+        if (fSamplers[i].visibility() & visibility) {
+            fSamplers[i].fShaderVar.appendDecl(fProgramBuilder->glslCaps(), out);
+            out->append(";\n");
+        }
+    }
 }
 
 void GrGLUniformHandler::bindUniformLocations(GrGLuint programID, const GrGLCaps& caps) {
@@ -68,6 +90,10 @@ void GrGLUniformHandler::bindUniformLocations(GrGLuint programID, const GrGLCaps
             GL_CALL(BindUniformLocation(programID, i, fUniforms[i].fVariable.c_str()));
             fUniforms[i].fLocation = i;
         }
+        for (int i = 0; i < fSamplers.count(); ++i) {
+            GL_CALL(BindUniformLocation(programID, i, fSamplers[i].fVariable.c_str()));
+            fSamplers[i].fLocation = i;
+        }
     }
 }
 
@@ -79,6 +105,11 @@ void GrGLUniformHandler::getUniformLocations(GrGLuint programID, const GrGLCaps&
             GL_CALL_RET(location, GetUniformLocation(programID, fUniforms[i].fVariable.c_str()));
             fUniforms[i].fLocation = location;
         }
+        for (int i = 0; i < fSamplers.count(); ++i) {
+            GrGLint location;
+            GL_CALL_RET(location, GetUniformLocation(programID, fSamplers[i].fVariable.c_str()));
+            fSamplers[i].fLocation = location;
+        }
     }
 }