Revert of Prevent duplicate content script injection defined in manifest.json

Revert of Prevent duplicate content script injection defined in manifest.json (patchset #9 id:160001 of https://codereview.chromium.org/2116613002/ )

Reason for revert:
Causes a renderer crash - http://crbug.com/631247

Original issue's description:
> Keeps track of scripts injected by extensions installed. Checks if a script is
> already injected, and injects a script only if it has not been injected.
>
> BUG=248627
> TEST= Run target browser_tests with
> --gtest_filter="ExtensionApiTest.ContentScript*"
>
> Committed: https://crrev.com/90d8dd145246616da02f5a54f1da1f5bfe6680e9
> Cr-Commit-Position: refs/heads/master@{#407016}

TBR=catmullings@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=248627
Committed: https://crrev.com/f05678d76cdf2f63b19e6716220ec1e951675856
Cr-Commit-Position: refs/heads/master@{#409109}

[Devlin, 2016-08-02 00:13:39]

The CQ bit was checked by rdevlin.cronin@chromium.org

[Devlin, 2016-08-02 00:13:39]

Created Revert of Prevent duplicate content script injection defined in
manifest.json

[commit-bot: I haz the power, 2016-08-02 00:13:55]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-02 01:12:01]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-08-02 01:16:21]

Description was changed from

==========
Revert of Prevent duplicate content script injection defined in manifest.json
(patchset #9 id:160001 of https://codereview.chromium.org/2116613002/ )

Reason for revert:
Causes a renderer crash - http://crbug.com/631247

Original issue's description:
> Keeps track of scripts injected by extensions installed. Checks if a script is
> already injected, and injects a script only if it has not been injected.
> 
> BUG=248627
> TEST= Run target browser_tests with
> --gtest_filter="ExtensionApiTest.ContentScript*"
> 
> Committed: https://crrev.com/90d8dd145246616da02f5a54f1da1f5bfe6680e9
> Cr-Commit-Position: refs/heads/master@{#407016}

TBR=catmullings@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=248627
==========

to

==========
Revert of Prevent duplicate content script injection defined in manifest.json
(patchset #9 id:160001 of https://codereview.chromium.org/2116613002/ )

Reason for revert:
Causes a renderer crash - http://crbug.com/631247

Original issue's description:
> Keeps track of scripts injected by extensions installed. Checks if a script is
> already injected, and injects a script only if it has not been injected.
>
> BUG=248627
> TEST= Run target browser_tests with
> --gtest_filter="ExtensionApiTest.ContentScript*"
>
> Committed: https://crrev.com/90d8dd145246616da02f5a54f1da1f5bfe6680e9
> Cr-Commit-Position: refs/heads/master@{#407016}

TBR=catmullings@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=248627

Committed: https://crrev.com/f05678d76cdf2f63b19e6716220ec1e951675856
Cr-Commit-Position: refs/heads/master@{#409109}
==========

[commit-bot: I haz the power, 2016-08-02 01:16:22]

Patchset 1 (id:??) landed as
https://crrev.com/f05678d76cdf2f63b19e6716220ec1e951675856
Cr-Commit-Position: refs/heads/master@{#409109}