cc: Add ImageManager to keep all the image locking in the same place.

cc/BUILD.gn

 # 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.
 
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 component("cc") {
   sources = [
     "animation/animation.cc",
@@ skipping 432 matching lines @@
     "scheduler/scheduler_settings.cc",
     "scheduler/scheduler_settings.h",
     "scheduler/scheduler_state_machine.cc",
     "scheduler/scheduler_state_machine.h",
     "scheduler/video_frame_controller.h",
     "tiles/eviction_tile_priority_queue.cc",
     "tiles/eviction_tile_priority_queue.h",
     "tiles/gpu_image_decode_controller.cc",
     "tiles/gpu_image_decode_controller.h",
     "tiles/image_decode_controller.h",
+    "tiles/image_manager.cc",
+    "tiles/image_manager.h",
     "tiles/mipmap_util.cc",
     "tiles/mipmap_util.h",
     "tiles/picture_layer_tiling.cc",
     "tiles/picture_layer_tiling.h",
     "tiles/picture_layer_tiling_set.cc",
     "tiles/picture_layer_tiling_set.h",
     "tiles/prioritized_tile.cc",
     "tiles/prioritized_tile.h",
     "tiles/raster_tile_priority_queue.cc",
     "tiles/raster_tile_priority_queue.h",
@@ skipping 577 matching lines @@
     "//testing/perf",
     "//ui/gfx",
     "//ui/gfx/geometry",
     "//ui/gl",
     "//ui/gl:test_support",
   ]
 
   # This target should not require the Chrome executable to run.
   assert_no_deps = [ "//chrome" ]
 }