[Cronet] Fix two races/leaks in JavaUrlRequest

[Cronet]  Fix two races/leaks in JavaUrlRequest

The underlying InputStream and HttpURLConnection were accessed on different
threads which during cancellation could result in races resulting in leaks
that StrictMode catches. Shift all accesses to these variables to one
thread like the Chromium threading principles recommends.

BUG=726193
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester

Review-Url: https://codereview.chromium.org/2903193002
Cr-Original-Commit-Position: refs/heads/master@{#475945}
Review-Url: https://codereview.chromium.org/2915033002 .
Cr-Commit-Position: refs/branch-heads/3112@{#87}
Cr-Branched-From: b6460e24cf59f429d69de255538d0fc7a425ccf9-refs/heads/master@{#474897}
Committed: https://chromium.googlesource.com/chromium/src/+/8a145da80cb326dca497d43777003498ac38e2a4

[pauljensen, 2017-06-01 13:05:53]

Description was changed from

==========
[Cronet]  Fix two races/leaks in JavaUrlRequest

The underlying InputStream and HttpURLConnection were accessed on different
threads which during cancellation could result in races resulting in leaks
that StrictMode catches. Shift all accesses to these variables to one
thread like the Chromium threading principles recommends.

BUG=726193
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester

Review-Url: https://codereview.chromium.org/2903193002
Cr-Commit-Position: refs/heads/master@{#475945}
(cherry picked from commit 8f8aa43973e496a65d9eecfa3e6f8b8dd68432e7)
==========

to

==========
[Cronet]  Fix two races/leaks in JavaUrlRequest

The underlying InputStream and HttpURLConnection were accessed on different
threads which during cancellation could result in races resulting in leaks
that StrictMode catches. Shift all accesses to these variables to one
thread like the Chromium threading principles recommends.

BUG=726193
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester

Review-Url: https://codereview.chromium.org/2903193002
Cr-Original-Commit-Position: refs/heads/master@{#475945}
Review-Url: https://codereview.chromium.org/2915033002 .
Cr-Commit-Position: refs/branch-heads/3112@{#87}
Cr-Branched-From:
b6460e24cf59f429d69de255538d0fc7a425ccf9-refs/heads/master@{#474897}
Committed:
https://chromium.googlesource.com/chromium/src/+/8a145da80cb326dca497d4377700...
==========

[pauljensen, 2017-06-01 13:05:56]

Committed patchset #1 (id:1) manually as
8a145da80cb326dca497d43777003498ac38e2a4.