remove unneeded SkShader::validContext

src/effects/gradients/SkLinearGradient.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkLinearGradient.h"
 
 static inline int repeat_bits(int x, const int bits) {
@@ skipping 58 matching lines @@
 void SkLinearGradient::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writePoint(fStart);
     buffer.writePoint(fEnd);
 }
 
 size_t SkLinearGradient::contextSize() const {
     return sizeof(LinearGradientContext);
 }
 
-SkShader::Context* SkLinearGradient::createContext(const ContextRec& rec, void* storage) const {
-    if (!this->validContext(rec)) {
-        return NULL;
-    }
-
+SkShader::Context* SkLinearGradient::onCreateContext(const ContextRec& rec, void* storage) const {
     return SkNEW_PLACEMENT_ARGS(storage, LinearGradientContext, (*this, rec));
 }
 
 SkLinearGradient::LinearGradientContext::LinearGradientContext(
         const SkLinearGradient& shader, const ContextRec& rec)
     : INHERITED(shader, rec)
 {
     unsigned mask = SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask;
     if ((fDstToIndex.getType() & ~mask) == 0) {
         // when we dither, we are (usually) not const-in-Y
@@ skipping 481 matching lines @@
     str->append("SkLinearGradient (");
 
     str->appendf("start: (%f, %f)", fStart.fX, fStart.fY);
     str->appendf(" end: (%f, %f) ", fEnd.fX, fEnd.fY);
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif