Revert "Revert of Refactor get_salient_image_url.js to use DocumentImageExtractor"

Revert "Revert of Refactor get_salient_image_url.js to use DocumentImageExtractor"

This reverts commit 848594a8fd844879fede9f8663d279b1bfac8253. The initial CL was reverted because the Android GN build was failing to compile. GN files have been added.

Refactor get_salient_image_url.js to use the DocumentImageExtractor.
Move get_salient_image_url.js into components so it accessible for
iOS as well.

BUG=454623
Committed: https://crrev.com/caf0eb7531ff4e54c74a9d7db47e7ad033d99f44
Cr-Commit-Position: refs/heads/master@{#332203}

[Theresa, 2015-05-28 20:01:36]

ptal - I'm not sure why the tryjobs didn't throw a fit, but the Android (dbg) gn
builder failed to compile, so I added back the gn stuff.

[Theresa, 2015-05-28 20:13:55]

twellington@chromium.org changed reviewers:
+ jhawkins@chromium.org, jochen@chromium.org, kkimlabs@chromium.org

[Theresa, 2015-05-28 20:13:56]

ptal - I'm not sure why the tryjobs didn't throw a fit, but the Android (dbg) gn
builder failed to compile, so I added back the gn stuff.

[jochen (gone - plz use gerrit), 2015-05-29 11:21:40]

lgtm

[James Hawkins, 2015-05-29 18:45:38]

On 2015/05/29 11:21:40, jochen wrote:
> lgtm

LGTM, but please include the reason why this was reverted in the CL description.

[Theresa, 2015-06-01 15:03:13]

The CQ bit was checked by twellington@chromium.org

[commit-bot: I haz the power, 2015-06-01 15:03:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1153283005/160001

[commit-bot: I haz the power, 2015-06-01 16:20:04]

Committed patchset #9 (id:160001)

[commit-bot: I haz the power, 2015-06-01 16:23:33]

Patchset 9 (id:??) landed as
https://crrev.com/caf0eb7531ff4e54c74a9d7db47e7ad033d99f44
Cr-Commit-Position: refs/heads/master@{#332203}