Allow an external URL with FROM_API qualifier to be forwarded to ARC

Allow an external URL with FROM_API qualifier to be forwarded to ARC

for better AppAuth compatibility.

In a highly unusual situation, allowing FROM_API could trigger
infinite Chrome tab creation. This CL also adds code for detecting
and stopping the loop, just in case. End users will almost never
see the safety checks to kick in, though.

BUG=670465
TEST=unit_tests passed, also manually confirmed that when
 |always_ask_user| is true, "Always" preference set by
 the user is ignored.

Review-Url: https://codereview.chromium.org/2540013004
Cr-Commit-Position: refs/heads/master@{#436017}
(cherry picked from commit 0c7e06f5b85f0304bd62f61a9b2ae391e97f3183)

Committed: https://chromium.googlesource.com/chromium/src/+/f5d5e34508dfe64379c170ad1e3236b20c685b97

[Yusuke Sato, 2016-12-06 21:33:12]

Description was changed from

==========
Allow an external URL with FROM_API qualifier to be forwarded to ARC

for better AppAuth compatibility.

In a highly unusual situation, allowing FROM_API could trigger
infinite Chrome tab creation. This CL also adds code for detecting
and stopping the loop, just in case. End users will almost never
see the safety checks to kick in, though.

BUG=670465
TEST=unit_tests passed, also manually confirmed that when
 |always_ask_user| is true, "Always" preference set by
 the user is ignored.

Review-Url: https://codereview.chromium.org/2540013004
Cr-Commit-Position: refs/heads/master@{#436017}
(cherry picked from commit 0c7e06f5b85f0304bd62f61a9b2ae391e97f3183)
==========

to

==========
Allow an external URL with FROM_API qualifier to be forwarded to ARC

for better AppAuth compatibility.

In a highly unusual situation, allowing FROM_API could trigger
infinite Chrome tab creation. This CL also adds code for detecting
and stopping the loop, just in case. End users will almost never
see the safety checks to kick in, though.

BUG=670465
TEST=unit_tests passed, also manually confirmed that when
 |always_ask_user| is true, "Always" preference set by
 the user is ignored.

Review-Url: https://codereview.chromium.org/2540013004
Cr-Commit-Position: refs/heads/master@{#436017}
(cherry picked from commit 0c7e06f5b85f0304bd62f61a9b2ae391e97f3183)

Committed:
https://chromium.googlesource.com/chromium/src/+/f5d5e34508dfe64379c170ad1e32...
==========

[Yusuke Sato, 2016-12-06 21:33:14]

Committed patchset #1 (id:1) manually as
f5d5e34508dfe64379c170ad1e3236b20c685b97.