The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cf87bb1cf39b26f7127ba4cee4147c8d52966fd9

commit cf87bb1cf39b26f7127ba4cee4147c8d52966fd9
Author: oka <oka@chromium.org>
Date: Tue Dec 20 09:07:02 2016

Files App: Add metrics for background performance.

FileBrowser.Load.BackgroundScript:
  Time to initialize backend script to wait for events.
FileBrowser.Load.BackgroundLaunch:
  Time from onLaunched event is called to the window is created.
FileBrowser.Load.BackgroundRestart:
  Time to create a window on restart.

BUG= 675536 
TEST=manually confirmed on Linux that sane values are exported in
chrome://histograms

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2585193002
Cr-Commit-Position: refs/heads/master@{#439755}

[modify] https://crrev.com/cf87bb1cf39b26f7127ba4cee4147c8d52966fd9/tools/metrics/histograms/histograms.xml
[modify] https://crrev.com/cf87bb1cf39b26f7127ba4cee4147c8d52966fd9/ui/file_manager/file_manager/background/js/background.js
[modify] https://crrev.com/cf87bb1cf39b26f7127ba4cee4147c8d52966fd9/ui/file_manager/file_manager/background/js/background_scripts.js
[add] https://crrev.com/cf87bb1cf39b26f7127ba4cee4147c8d52966fd9/ui/file_manager/file_manager/background/js/metrics_start.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/574d1b6b15c21078fdb15f2716736a0d4c24ea87

commit 574d1b6b15c21078fdb15f2716736a0d4c24ea87
Author: oka <oka@chromium.org>
Date: Tue Dec 20 11:37:20 2016

Files App: add more performance metrics for foreground initialization.

FileBrowser.Load.ImportElements:
    Time to initialize the polymer elements.
FileBrowser.Load.InitBackgroundPage:
    Time to initialize the background page.
FileBrowser.Load.InitDocuments:
    Time to initialize the background page and the elements.
FileBrowser.Load.InitSettings:
    Time to restore user settings.
FileBrowser.Load.InitUI:
    Time to initialize all UI after all elements are initialized.

BUG= 675536 
TEST=manually confirmed on Linux that the above values are exported to chrome://histograms.

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2589693002
Cr-Commit-Position: refs/heads/master@{#439769}

[modify] https://crrev.com/574d1b6b15c21078fdb15f2716736a0d4c24ea87/tools/metrics/histograms/histograms.xml
[modify] https://crrev.com/574d1b6b15c21078fdb15f2716736a0d4c24ea87/ui/file_manager/file_manager/foreground/js/elements_importer.js
[modify] https://crrev.com/574d1b6b15c21078fdb15f2716736a0d4c24ea87/ui/file_manager/file_manager/foreground/js/file_manager.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a91cd206d821a7c61cb04057f4c3bd4da5fe556f

commit a91cd206d821a7c61cb04057f4c3bd4da5fe556f
Author: oka <oka@chromium.org>
Date: Tue Dec 20 14:36:33 2016

Quick view lazy load part 1: initialize controllers lazily.

Initialize MetadataBoxController and QuickViewController only when
it is needed.
This CL doesn't lazy load polymer element of quick view. It will be
done with subsequent CL(s).

BUG= 675536 
TEST=manually.
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2589133002
Cr-Commit-Position: refs/heads/master@{#439797}

[modify] https://crrev.com/a91cd206d821a7c61cb04057f4c3bd4da5fe556f/ui/file_manager/file_manager/foreground/js/file_manager.js
[modify] https://crrev.com/a91cd206d821a7c61cb04057f4c3bd4da5fe556f/ui/file_manager/file_manager/foreground/js/metadata_box_controller.js
[modify] https://crrev.com/a91cd206d821a7c61cb04057f4c3bd4da5fe556f/ui/file_manager/file_manager/foreground/js/quick_view_controller.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0667c0d63e43c625009d47031fbe9929cdac9864

commit 0667c0d63e43c625009d47031fbe9929cdac9864
Author: oka <oka@chromium.org>
Date: Wed Dec 21 05:46:20 2016

Quick view lazy load: initialize quick view element lazily.

Sped up files app launch speed by ~100ms (on Linux) by lazily loading
files-quick-view and files-metadata-box elements.

BUG= 675536 
TEST=manually.
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2594613002
Cr-Commit-Position: refs/heads/master@{#440031}

[modify] https://crrev.com/0667c0d63e43c625009d47031fbe9929cdac9864/ui/file_manager/file_manager/foreground/elements/elements_bundle.html
[modify] https://crrev.com/0667c0d63e43c625009d47031fbe9929cdac9864/ui/file_manager/file_manager/foreground/js/quick_view_controller.js

I confirmed latency decreased on Canary to ~1.4s. Marking the bug as fixed.
https://uma.googleplex.com/p/chrome/timeline_v2/?sid=d6f179d6ee21bc0675d774798b547da4