SkBitmap and SkPixelRef no longer need lock/unlock

chrome/browser/chromeos/login/screenshot_testing/SkPMetric.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // WARNING! This file is copied from third_party/skia/tools/skpdiff and slightly
 // modified to be compilable outside Skia and suit chromium style. Some comments
 // can make no sense.
 // TODO(elizavetai): remove this file and reuse the original one in Skia
 
 #include <cmath>
@@ skipping 121 matching lines @@
       return false;
     }
     bitmap = &bm8888;
   }
 
   int width = bitmap->width();
   int height = bitmap->height();
   DCHECK(outImageLAB->width == width);
   DCHECK(outImageLAB->height == height);
 
-  bitmap->lockPixels();
   RGB rgb;
   LAB lab;
   for (int y = 0; y < height; y++) {
     unsigned char* row = (unsigned char*)bitmap->getAddr(0, y);
     for (int x = 0; x < width; x++) {
       // Perform gamma correction which is assumed to be 2.2
       rgb.r = SkPMetricUtil::get_gamma(row[x * 4 + 2]);
       rgb.g = SkPMetricUtil::get_gamma(row[x * 4 + 1]);
       rgb.b = SkPMetricUtil::get_gamma(row[x * 4 + 0]);
       adobergb_to_cielab(rgb.r, rgb.g, rgb.b, &lab);
       outImageLAB->writePixel(x, y, lab);
     }
   }
-  bitmap->unlockPixels();
   return true;
 }
 
 // From Barten SPIE 1989
 static float contrast_sensitivity(float cyclesPerDegree, float luminance) {
   float a = 440.0f * powf(1.0f + 0.7f / luminance, -0.2f);
   float b = 0.3f * powf(1.0f + 100.0f / luminance, 0.15f);
   float exp = expf(-b * cyclesPerDegree);
   float root = sqrtf(1.0f + 0.06f * expf(b * cyclesPerDegree));
   if (!SkScalarIsFinite(exp) || !SkScalarIsFinite(root)) {
@@ skipping 304 matching lines @@
   if (!bitmap_to_cielab(baseline, &baselineLAB) ||
       !bitmap_to_cielab(test, &testLAB)) {
     return true;
   }
 
   result->poiCount = 0;
   result->result = pmetric(&baselineLAB, &testLAB, &result->poiCount);
 
   return true;
 }