Revert of remove colorfilter native-565 support. complicating w/ no real value.

src/core/SkFilterShader.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkFilterShader.h"
 
 #include "SkColorFilter.h"
@@ skipping 28 matching lines @@
     buffer.writeFlattenable(fShader);
     buffer.writeFlattenable(fFilter);
 }
 
 uint32_t SkFilterShader::FilterShaderContext::getFlags() const {
     const SkFilterShader& filterShader = static_cast<const SkFilterShader&>(fShader);
 
     uint32_t shaderF = fShaderContext->getFlags();
     uint32_t filterF = filterShader.fFilter->getFlags();
 
-    // filters don't support 16bit, so clear the matching bit in the shader
-    shaderF &= ~SkShader::kHasSpan16_Flag;
-
+    // if the filter doesn't support 16bit, clear the matching bit in the shader
+    if (!(filterF & SkColorFilter::kHasFilter16_Flag)) {
+        shaderF &= ~SkShader::kHasSpan16_Flag;
+    }
     // if the filter might change alpha, clear the opaque flag in the shader
     if (!(filterF & SkColorFilter::kAlphaUnchanged_Flag)) {
-        shaderF &= ~SkShader::kOpaqueAlpha_Flag;
+        shaderF &= ~(SkShader::kOpaqueAlpha_Flag | SkShader::kHasSpan16_Flag);
     }
     return shaderF;
 }
 
 SkShader::Context* SkFilterShader::onCreateContext(const ContextRec& rec, void* storage) const {
     char* shaderContextStorage = (char*)storage + sizeof(FilterShaderContext);
     SkShader::Context* shaderContext = fShader->createContext(rec, shaderContextStorage);
     if (NULL == shaderContext) {
         return NULL;
     }
@@ skipping 14 matching lines @@
     fShaderContext->~Context();
 }
 
 void SkFilterShader::FilterShaderContext::shadeSpan(int x, int y, SkPMColor result[], int count) {
     const SkFilterShader& filterShader = static_cast<const SkFilterShader&>(fShader);
 
     fShaderContext->shadeSpan(x, y, result, count);
     filterShader.fFilter->filterSpan(result, count, result);
 }
 
+void SkFilterShader::FilterShaderContext::shadeSpan16(int x, int y, uint16_t result[], int count) {
+    const SkFilterShader& filterShader = static_cast<const SkFilterShader&>(fShader);
+
+    SkASSERT(fShaderContext->getFlags() & SkShader::kHasSpan16_Flag);
+    SkASSERT(filterShader.fFilter->getFlags() & SkColorFilter::kHasFilter16_Flag);
+
+    fShaderContext->shadeSpan16(x, y, result, count);
+    filterShader.fFilter->filterSpan16(result, count, result);
+}
+
 #ifndef SK_IGNORE_TO_STRING
 void SkFilterShader::toString(SkString* str) const {
     str->append("SkFilterShader: (");
 
     str->append("Shader: ");
     fShader->toString(str);
     str->append(" Filter: ");
     // TODO: add "fFilter->toString(str);" once SkColorFilter::toString is added
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif