Changed SkLightingShader API to take in a shader as color source

src/core/SkLightingShader.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapProcShader.h"
 #include "SkBitmapProcState.h"
 #include "SkColor.h"
@@ skipping 447 matching lines @@
                                                          void* storage) const {
 
     size_t heapRequired = fDiffuseShader->contextSize(rec) + fNormalSource->providerSize(rec);
     void* heapAllocated = malloc(heapRequired); // Freed on ~LightingShaderContext()
 
     void* diffuseContextStorage = (char*)heapAllocated;
 
     SkShader::Context* diffuseContext = fDiffuseShader->createContext(rec, diffuseContextStorage);
 
     void* normalProviderStorage = (char*)heapAllocated + fDiffuseShader->contextSize(rec);
-    SkNormalSource::Provider* normalProvider =
-            fNormalSource->asProvider(rec, normalProviderStorage);
+    SkNormalSource::Provider* normalProvider = fNormalSource->asProvider(rec,
+                                                                         normalProviderStorage);
     if (!normalProvider) {
         diffuseContext->~Context();
         free(heapAllocated);
         return nullptr;
     }
 
     return new (storage) LightingShaderContext(*this, rec, diffuseContext, normalProvider,
                                                heapAllocated);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
-sk_sp<SkShader> SkLightingShader::Make(const SkBitmap& diffuse, sk_sp<SkLights> lights,
-            const SkMatrix* diffLocalM, sk_sp<SkNormalSource> normalSource) {
-    if (diffuse.isNull() || SkBitmapProcShader::BitmapIsTooBig(diffuse)) {
-        return nullptr;
-    }
-
-    if (!normalSource) {
+sk_sp<SkShader> SkLightingShader::Make(sk_sp<SkShader> diffuseShader,
+        sk_sp<SkNormalSource> normalSource, sk_sp<SkLights> lights) {
+    if (!diffuseShader || !normalSource) {
+        // TODO: Use paint's color in absence of a diffuseShader
         // TODO: Use a default implementation of normalSource instead
         return nullptr;
     }
 
-    // TODO: support other tile modes
-    sk_sp<SkShader> diffuseShader = SkBitmapProcShader::MakeBitmapShader(diffuse,
-            SkShader::kClamp_TileMode, SkShader::kClamp_TileMode, diffLocalM);
-
     return sk_make_sp<SkLightingShaderImpl>(std::move(diffuseShader), std::move(normalSource),
                                             std::move(lights));
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkLightingShader)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkLightingShaderImpl)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END
 
 ///////////////////////////////////////////////////////////////////////////////