Moved FolderImageSource class to a separate file.

Moved FolderImageSource class to a separate file.

Previously, this was a private class in app_list_folder_item.cc. It will
soon be required from multiple locations (to generate folder icons), so
it deserves its own file.

Also moved methods/constants relating to the tiny icon size/position
into static methods of this class (as needed by various clients).

BUG=425444
Committed: https://crrev.com/793ecbcdd2730ac94f6cdc10e08d1b7c4c29e83d
Cr-Commit-Position: refs/heads/master@{#301028}

[Matt Giuca, 2014-10-21 07:47:20]

mgiuca@chromium.org changed reviewers:
+ calamity@chromium.org

[calamity, 2014-10-23 05:41:18]

lgtm

https://codereview.chromium.org/657793004/diff/1/ui/app_list/folder_image_sou...
File ui/app_list/folder_image_source.h (right):

https://codereview.chromium.org/657793004/diff/1/ui/app_list/folder_image_sou...
ui/app_list/folder_image_source.h:27: 
nit: remove newline.

[Matt Giuca, 2014-10-23 06:32:38]

https://codereview.chromium.org/657793004/diff/1/ui/app_list/folder_image_sou...
File ui/app_list/folder_image_source.h (right):

https://codereview.chromium.org/657793004/diff/1/ui/app_list/folder_image_sou...
ui/app_list/folder_image_source.h:27: 
On 2014/10/23 05:41:18, calamity wrote:
> nit: remove newline.

Done.

[Matt Giuca, 2014-10-23 06:32:45]

The CQ bit was checked by mgiuca@chromium.org

[commit-bot: I haz the power, 2014-10-23 06:33:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/657793004/20001

[commit-bot: I haz the power, 2014-10-23 06:36:21]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-10-23 06:36:22]

Try jobs failed on following builders:
  linux_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/linux_gpu/builds/...)
  mac_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/mac_gpu/builds/72426)
  android_aosp on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_aosp/bu...)
  linux_chromium_chromeos_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_compile_dbg_32 on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  mac_chromium_rel on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel/...)
  win8_chromium_rel on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_rel...)
  win_chromium_x64_rel on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Matt Giuca, 2014-10-23 23:53:58]

The CQ bit was checked by mgiuca@chromium.org

[commit-bot: I haz the power, 2014-10-23 23:55:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/657793004/40001

[commit-bot: I haz the power, 2014-10-24 00:16:56]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-10-24 00:16:57]

Try jobs failed on following builders:
  linux_chromium_gn_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Matt Giuca, 2014-10-24 01:03:19]

The CQ bit was checked by mgiuca@chromium.org

[commit-bot: I haz the power, 2014-10-24 01:05:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/657793004/60001

[commit-bot: I haz the power, 2014-10-24 02:01:37]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2014-10-24 02:02:54]

Patchset 4 (id:??) landed as
https://crrev.com/793ecbcdd2730ac94f6cdc10e08d1b7c4c29e83d
Cr-Commit-Position: refs/heads/master@{#301028}