Fix conversion from enum to bool error.

src/core/SkImageGenerator.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkImageGenerator.h"
 
 bool SkImageGenerator::getInfo(SkImageInfo* info) {
@@ skipping 104 matching lines @@
     return NULL;
 }
 
 bool SkImageGenerator::onGetInfo(SkImageInfo*) {
     return false;
 }
 
 #ifdef SK_SUPPORT_LEGACY_IMAGE_GENERATOR_RETURN
 bool SkImageGenerator::onGetPixels(const SkImageInfo&, void*, size_t,
                                                        SkPMColor*, int*) {
-    return kUnimplemented;
+    return false;
 }
 #endif
 SkImageGenerator::Result SkImageGenerator::onGetPixelsEnum(const SkImageInfo& info, void* pixels,
                                                            size_t rowBytes, SkPMColor* colors,
                                                            int* colorCount) {
 #ifdef SK_SUPPORT_LEGACY_IMAGE_GENERATOR_RETURN
     if (this->onGetPixels(info, pixels, rowBytes, colors, colorCount)) {
         return kSuccess;
     }
 #endif
     return kUnimplemented;
 }