SkBitmap and SkPixelRef no longer need lock/unlock

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

Index: chrome/browser/chromeos/login/screenshot_testing/SkPMetric.cpp
diff --git a/chrome/browser/chromeos/login/screenshot_testing/SkPMetric.cpp b/chrome/browser/chromeos/login/screenshot_testing/SkPMetric.cpp
index 0f71ad5d94416c7cdb47acbb4106fca78cf6f31a..c551c5044c68105fffd690cb43c61dd402289101 100644
--- a/chrome/browser/chromeos/login/screenshot_testing/SkPMetric.cpp
+++ b/chrome/browser/chromeos/login/screenshot_testing/SkPMetric.cpp
@@ -139,7 +139,6 @@ static bool bitmap_to_cielab(const SkBitmap* bitmap, ImageLAB* outImageLAB) {
   DCHECK(outImageLAB->width == width);
   DCHECK(outImageLAB->height == height);
 
-  bitmap->lockPixels();
   RGB rgb;
   LAB lab;
   for (int y = 0; y < height; y++) {
@@ -153,7 +152,6 @@ static bool bitmap_to_cielab(const SkBitmap* bitmap, ImageLAB* outImageLAB) {
       outImageLAB->writePixel(x, y, lab);
     }
   }
-  bitmap->unlockPixels();
   return true;
 }