Add SkColorSpace::Equals() API

src/codec/SkJpegCodec.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 "SkCodec.h"
 #include "SkMSAN.h"
 #include "SkJpegCodec.h"
@@ skipping 457 matching lines @@
         num -= 1;
         calc_output_dimensions(&dinfo, num, denom);
     }
 
     fDecoderMgr->dinfo()->scale_num = num;
     fDecoderMgr->dinfo()->scale_denom = denom;
     return true;
 }
 
 static bool needs_color_xform(const SkImageInfo& dstInfo, const SkImageInfo& srcInfo) {
-    // FIXME (msarett):
-    // Do a better check for color space equality.
     return (kRGBA_F16_SkColorType == dstInfo.colorType()) ||
-           (dstInfo.colorSpace() && (dstInfo.colorSpace() != srcInfo.colorSpace()));
+           (dstInfo.colorSpace() && !SkColorSpace::Equals(srcInfo.colorSpace(),
+                                                          dstInfo.colorSpace()));
 }
 
 int SkJpegCodec::readRows(const SkImageInfo& dstInfo, void* dst, size_t rowBytes, int count) {
     // Set the jump location for libjpeg-turbo errors
     if (setjmp(fDecoderMgr->getJmpBuf())) {
         return 0;
     }
 
     // When fSwizzleSrcRow is non-null, it means that we need to swizzle.  In this case,
     // we will always decode into fSwizzlerSrcRow before swizzling into the next buffer.
@@ skipping 501 matching lines @@
 
         JDIMENSION linesRead = jpeg_read_raw_data(dinfo, yuv, numRowsPerBlock);
         if (linesRead < remainingRows) {
             // FIXME: Handle incomplete YUV decodes without signalling an error.
             return kInvalidInput;
         }
     }
 
     return kSuccess;
 }