SkBitmap and SkPixelRef no longer need lock/unlock

ui/gfx/canvas.cc

 // Copyright (c) 2012 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.
 
 #include "ui/gfx/canvas.h"
 
 #include <cmath>
 #include <limits>
 
 #include "base/i18n/rtl.h"
@@ skipping 496 matching lines @@
                                         shader_scale));
   return true;
 }
 
 void Canvas::Transform(const gfx::Transform& transform) {
   canvas_->concat(transform.matrix());
 }
 
 SkBitmap Canvas::GetBitmap() const {
   DCHECK(bitmap_);
-  SkBitmap bitmap = bitmap_.value();
-  // When the bitmap is copied, it shares the underlying pixelref, but doesn't
-  // initialize pixels unless they are locked. Hence, ensure that the returned
-  // bitmap keeps the pixelref alive by locking it. Note that the dtor of
-  // SkBitmap will unlock the pixelrefs, so this won't leak. Also note that
-  // moving SkBitmap retains the same lock as the source, so the caller
-  // will receive a locked-pixels bitmap.
-  bitmap.lockPixels();
-  return bitmap;
+  return bitmap_.value();
 }
 
 bool Canvas::IntersectsClipRect(const SkRect& rect) {
   SkRect clip;
   return canvas_->getLocalClipBounds(&clip) && clip.intersects(rect);
 }
 
 void Canvas::DrawImageIntHelper(const ImageSkiaRep& image_rep,
                                 int src_x,
                                 int src_y,
@@ skipping 54 matching lines @@
   bitmap_.emplace();
   bitmap_->allocPixels(info);
   // Ensure that the bitmap is zeroed, since the code expects that.
   memset(bitmap_->getPixels(), 0, bitmap_->getSafeSize());
 
   owned_canvas_ = cc::SkiaPaintCanvas(bitmap_.value());
   return &owned_canvas_.value();
 }
 
 }  // namespace gfx