The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b

commit 83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b
Author: khushalsagar <khushalsagar@chromium.org>
Date: Sat May 06 19:13:14 2017

cc: Update discardable image metadata generation to get PaintImages.

The process of generating the metadata for DrawImages involves
rastering the paint ops on an analysis canvas to capture SkImages. Since
the ops now store PaintImages which are required in the raster pipeline,
this change updates this step to directly iterate through the ops stored
in the buffer and add images onto the map.

We still maintain an SkNoDrawCanvas to track the transform, clip and
saved paints state from the non-drawing ops.

BUG= 715886 
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2842333003
Cr-Commit-Position: refs/heads/master@{#469873}

[modify] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/paint/BUILD.gn
[modify] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/paint/discardable_image_map.cc
[modify] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/paint/discardable_image_map.h
[modify] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/paint/discardable_image_map_unittest.cc
[add] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/paint/discardable_image_store.cc
[add] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/paint/discardable_image_store.h
[modify] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/paint/display_item_list.cc
[modify] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/paint/display_item_list.h
[modify] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/paint/paint_op_buffer.h
[modify] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/raster/image_hijack_canvas.cc
[modify] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/raster/image_hijack_canvas.h
[modify] https://crrev.com/83f8bbb8ac2dbe76c00360bfd7c99ac09a458d0b/cc/raster/image_hijack_canvas_unittest.cc