Improve the page download:

Improve the page download:

- observe page loading in the current tab and captrue it when it is ready directly from the tab.
- if tab renavigates/closes, pass the request back to RequestCoordinator

BUG=654955
Review-Url: https://codereview.chromium.org/2412823002
Cr-Commit-Position: refs/heads/master@{#425077}
(cherry picked from commit 02d38c0b50c55dadb98039dbc58a70ad2c7c8a15)

Committed: https://chromium.googlesource.com/chromium/src/+/e6afa7cf3c0dd8655dad4b40cb74abe3c3ba8078

[Dmitry Titov, 2016-10-14 01:00:02]

Description was changed from

==========
Improve the page download:

- observe page loading in the current tab and captrue it when it is ready
directly from the tab.
- if tab renavigates/closes, pass the request back to RequestCoordinator

BUG=654955

Review-Url: https://codereview.chromium.org/2412823002
Cr-Commit-Position: refs/heads/master@{#425077}
(cherry picked from commit 02d38c0b50c55dadb98039dbc58a70ad2c7c8a15)
==========

to

==========
Improve the page download:

- observe page loading in the current tab and captrue it when it is ready
directly from the tab.
- if tab renavigates/closes, pass the request back to RequestCoordinator

BUG=654955

Review-Url: https://codereview.chromium.org/2412823002
Cr-Commit-Position: refs/heads/master@{#425077}
(cherry picked from commit 02d38c0b50c55dadb98039dbc58a70ad2c7c8a15)

Committed:
https://chromium.googlesource.com/chromium/src/+/e6afa7cf3c0dd8655dad4b40cb74...
==========

[Dmitry Titov, 2016-10-14 01:00:04]

Committed patchset #1 (id:1) manually as
e6afa7cf3c0dd8655dad4b40cb74abe3c3ba8078.