cc: Add image decode control in the compositor.

This patch reworks ImageDecodeController and the surrounding
system to give control over image decodes to the compositor.

Perf note:

This is disabled on android, and should only affect desktop.
That being said, this patch changes the behavior with
respect to image decodes, so some perf changes are expected.

BUG=516751
R=enne, reed1
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1418573002

Cr-Commit-Position: refs/heads/master@{#370188}

• cc/BUILD.gn[diff]
• cc/cc.gyp[diff]
• cc/cc_tests.gyp[diff]
• cc/layers/picture_layer_impl.cc[diff]
• cc/playback/decoded_draw_image.h[Added - diff]
• cc/playback/discardable_image_map.cc[diff]
• cc/playback/discardable_image_map.h[diff]
• cc/playback/display_item_list.cc[diff]
• cc/playback/display_item_list.h[diff]
• cc/playback/display_list_raster_source.cc[diff]
• cc/playback/display_list_raster_source.h[diff]
• cc/playback/draw_image.cc[Added - diff]
• cc/playback/draw_image.h[diff]
• cc/tiles/image_decode_controller.cc[diff]
• cc/tiles/image_decode_controller.h[diff]
• cc/tiles/image_decode_controller_unittest.cc[Added - diff]
• cc/tiles/tile_manager.cc[diff]
• cc/tiles/tile_manager.h[diff]
• content/renderer/render_thread_impl.cc[diff]
• third_party/WebKit/LayoutTests/TestExpectations[diff]