[ash-md] Reduce thread hopping for cheap wallpaper color extraction.

[ash-md] Reduce thread hopping for cheap wallpaper color extraction.

Recent optimizations to the color_analysis::CalculateProminentColorOfBitmap()
has made it more expensive to perform color extraction asynchronously in some
cases. This change uses a simple image size heuristic to decide whether to
extract colors synchronously or asynchronously.

The optimizations made the 0-3 minute scale for the
'Ash.Wallpaper.TimeSpentExtractingColors' histogram overkill so it was replaced
with 'Ash.Wallpaper.ColorExtraction.Durations' one which uses a 0-10 second
scale.

This change also includes a new 'Ash.Wallpaper.ColorExtraction.UserDelay'
histogram that includes the thread switching delays incurred by asynchronous
calculations.

BUG=595010, 712714
TEST=components_unittests --gtest_filter=*WallPaperColorCalculator*yncTest*

Review-Url: https://codereview.chromium.org/2824883006
Cr-Commit-Position: refs/heads/master@{#467075}
(cherry picked from commit e4135c8d12a6554d16e3bf16a8b79bb6462aa7d8)

Review-Url: https://codereview.chromium.org/2849163002 .
Cr-Commit-Position: refs/branch-heads/3071@{#324}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/b04dec51600619369fb66ae642960d5df26bdbcd

[bruthig, 2017-05-01 16:20:40]

Description was changed from

==========
[ash-md] Reduce thread hopping for cheap wallpaper color extraction.

Recent optimizations to the color_analysis::CalculateProminentColorOfBitmap()
has made it more expensive to perform color extraction asynchronously in some
cases. This change uses a simple image size heuristic to decide whether to
extract colors synchronously or asynchronously.

The optimizations made the 0-3 minute scale for the
'Ash.Wallpaper.TimeSpentExtractingColors' histogram overkill so it was replaced
with 'Ash.Wallpaper.ColorExtraction.Durations' one which uses a 0-10 second
scale.

This change also includes a new 'Ash.Wallpaper.ColorExtraction.UserDelay'
histogram that includes the thread switching delays incurred by asynchronous
calculations.

BUG=595010, 712714
TEST=components_unittests --gtest_filter=*WallPaperColorCalculator*yncTest*

Review-Url: https://codereview.chromium.org/2824883006
Cr-Commit-Position: refs/heads/master@{#467075}
(cherry picked from commit e4135c8d12a6554d16e3bf16a8b79bb6462aa7d8)
==========

to

==========
[ash-md] Reduce thread hopping for cheap wallpaper color extraction.

Recent optimizations to the color_analysis::CalculateProminentColorOfBitmap()
has made it more expensive to perform color extraction asynchronously in some
cases. This change uses a simple image size heuristic to decide whether to
extract colors synchronously or asynchronously.

The optimizations made the 0-3 minute scale for the
'Ash.Wallpaper.TimeSpentExtractingColors' histogram overkill so it was replaced
with 'Ash.Wallpaper.ColorExtraction.Durations' one which uses a 0-10 second
scale.

This change also includes a new 'Ash.Wallpaper.ColorExtraction.UserDelay'
histogram that includes the thread switching delays incurred by asynchronous
calculations.

BUG=595010, 712714
TEST=components_unittests --gtest_filter=*WallPaperColorCalculator*yncTest*

Review-Url: https://codereview.chromium.org/2824883006
Cr-Commit-Position: refs/heads/master@{#467075}
(cherry picked from commit e4135c8d12a6554d16e3bf16a8b79bb6462aa7d8)

Review-Url: https://codereview.chromium.org/2849163002 .
Cr-Commit-Position: refs/branch-heads/3071@{#324}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/b04dec51600619369fb66ae64296...
==========

[bruthig, 2017-05-01 16:20:41]

Committed patchset #1 (id:1) manually as
b04dec51600619369fb66ae642960d5df26bdbcd.