Fix loading success.html at the end of chrome://chrome-signin flow

Fix loading success.html at the end of chrome://chrome-signin flow

This CL lists success.html as an webview accessible resource for
the sign-in extension.

This CL adds an exception for sign-in extension when for loading
webview accessible resources.

BUG=709117
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2831183003
Cr-Commit-Position: refs/heads/master@{#467739}
(cherry picked from commit 8fdab62089307f5fe2307335dd1c71c4c6661867)

Review-Url: https://codereview.chromium.org/2857583002 .
Cr-Commit-Position: refs/branch-heads/3071@{#347}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/89b5bfc4897cbc1efcbff39bd568386cc24f4da6

[msarda, 2017-05-02 13:40:02]

Description was changed from

==========
Fix loading success.html at the end of chrome://chrome-signin flow

This CL lists success.html as an webview accessible resource for
the sign-in extension.

This CL adds an exception for sign-in extension when for loading
webview accessible resources.

BUG=709117
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2831183003
Cr-Commit-Position: refs/heads/master@{#467739}
(cherry picked from commit 8fdab62089307f5fe2307335dd1c71c4c6661867)
==========

to

==========
Fix loading success.html at the end of chrome://chrome-signin flow

This CL lists success.html as an webview accessible resource for
the sign-in extension.

This CL adds an exception for sign-in extension when for loading
webview accessible resources.

BUG=709117
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2831183003
Cr-Commit-Position: refs/heads/master@{#467739}
(cherry picked from commit 8fdab62089307f5fe2307335dd1c71c4c6661867)

Review-Url: https://codereview.chromium.org/2857583002 .
Cr-Commit-Position: refs/branch-heads/3071@{#347}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/89b5bfc4897cbc1efcbff39bd568...
==========

[msarda, 2017-05-02 13:40:04]

Committed patchset #1 (id:1) manually as
89b5bfc4897cbc1efcbff39bd568386cc24f4da6.