Allow a preconnecting job to a HTTP2 proxy server based on privacy mode

Allow a preconnecting job to a HTTP2 proxy server based on privacy mode

Currently, one preconnect job is allowed in-flight for one proxy server.
This CL changes it to allow one in-flight preconnect job for one
(proxy server, privacy mode) tuple. This is needed since requests that
use different privacy modes cannot share the same connection.

BUG=667471
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester

Review-Url: https://codereview.chromium.org/2648593002
Cr-Commit-Position: refs/heads/master@{#445392}
(cherry picked from commit 37e33d58c076a55df84e0187538d6ec8996c206b)

Review-Url: https://codereview.chromium.org/2707053006 .
Cr-Commit-Position: refs/branch-heads/2987@{#649}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed: https://chromium.googlesource.com/chromium/src/+/9de7914b0e652585d4ac07303a949fbf1b19f09c

[tbansal1, 2017-02-22 23:26:02]

Description was changed from

==========
Allow a preconnecting job to a HTTP2 proxy server based on privacy mode

Currently, one preconnect job is allowed in-flight for one proxy server.
This CL changes it to allow one in-flight preconnect job for one
(proxy server, privacy mode) tuple. This is needed since requests that
use different privacy modes cannot share the same connection.

BUG=667471
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester

Review-Url: https://codereview.chromium.org/2648593002
Cr-Commit-Position: refs/heads/master@{#445392}
(cherry picked from commit 37e33d58c076a55df84e0187538d6ec8996c206b)
==========

to

==========
Allow a preconnecting job to a HTTP2 proxy server based on privacy mode

Currently, one preconnect job is allowed in-flight for one proxy server.
This CL changes it to allow one in-flight preconnect job for one
(proxy server, privacy mode) tuple. This is needed since requests that
use different privacy modes cannot share the same connection.

BUG=667471
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester

Review-Url: https://codereview.chromium.org/2648593002
Cr-Commit-Position: refs/heads/master@{#445392}
(cherry picked from commit 37e33d58c076a55df84e0187538d6ec8996c206b)

Review-Url: https://codereview.chromium.org/2707053006 .
Cr-Commit-Position: refs/branch-heads/2987@{#649}
Cr-Branched-From:
ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed:
https://chromium.googlesource.com/chromium/src/+/9de7914b0e652585d4ac07303a94...
==========

[tbansal1, 2017-02-22 23:26:03]

Committed patchset #1 (id:1) manually as
9de7914b0e652585d4ac07303a949fbf1b19f09c.