Revert of Allow use of Mojo/V8 ProxyResolvers with URLRequestContextBuilder.

Revert of Allow use of Mojo/V8 ProxyResolvers with URLRequestContextBuilder. (patchset #10 id:280001 of https://codereview.chromium.org/2881613002/ )

Reason for revert:
http://crbug.com/724471  V8InProcessShutdownWithHungRequest flaky on a cronet bot

Original issue's description:
> Allow use of Mojo/V8 ProxyResolvers with URLRequestContextBuilder.
> 
> This adds URLRequestContextBuilderV8, which can construct a
> URLRequestContext using either type of ProxyResolver. When using such
> a resolver, the ProxyService will fetch requests using the
> URLRequestContext that was created with the builder.
> 
> Added a subclass instead of modifying URLRequestContextBuilder so it
> can continue to be used without depending on V8.
> 
> BUG=717253
> 
> Review-Url: https://codereview.chromium.org/2881613002
> Cr-Commit-Position: refs/heads/master@{#472439}
> Committed: https://chromium.googlesource.com/chromium/src/+/f4fc1f04fe1a0d835a508720fdd90841a8d1583b

TBR=eroman@chromium.org,mmenke@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=717253
Review-Url: https://codereview.chromium.org/2888043008
Cr-Commit-Position: refs/heads/master@{#473182}
Committed: https://chromium.googlesource.com/chromium/src/+/b7060318b0cc8ccf7f4572104d08580919f1a733

[pasko, 2017-05-19 12:41:00]

The CQ bit was checked by pasko@chromium.org

[pasko, 2017-05-19 12:41:02]

Created Revert of Allow use of Mojo/V8 ProxyResolvers with
URLRequestContextBuilder.

[commit-bot: I haz the power, 2017-05-19 12:41:27]

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, 2017-05-19 14:41:14]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1495197660440430, "parent_rev":
"b68636d648c64b4312aa050486b74cccd6ceece4", "commit_rev":
"b7060318b0cc8ccf7f4572104d08580919f1a733"}

[commit-bot: I haz the power, 2017-05-19 14:41:31]

Description was changed from

==========
Revert of Allow use of Mojo/V8 ProxyResolvers with URLRequestContextBuilder.
(patchset #10 id:280001 of https://codereview.chromium.org/2881613002/ )

Reason for revert:
http://crbug.com/724471  V8InProcessShutdownWithHungRequest flaky on a cronet
bot

Original issue's description:
> Allow use of Mojo/V8 ProxyResolvers with URLRequestContextBuilder.
> 
> This adds URLRequestContextBuilderV8, which can construct a
> URLRequestContext using either type of ProxyResolver. When using such
> a resolver, the ProxyService will fetch requests using the
> URLRequestContext that was created with the builder.
> 
> Added a subclass instead of modifying URLRequestContextBuilder so it
> can continue to be used without depending on V8.
> 
> BUG=717253
> 
> Review-Url: https://codereview.chromium.org/2881613002
> Cr-Commit-Position: refs/heads/master@{#472439}
> Committed:
https://chromium.googlesource.com/chromium/src/+/f4fc1f04fe1a0d835a508720fdd9...

TBR=eroman@chromium.org,mmenke@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=717253
==========

to

==========
Revert of Allow use of Mojo/V8 ProxyResolvers with URLRequestContextBuilder.
(patchset #10 id:280001 of https://codereview.chromium.org/2881613002/ )

Reason for revert:
http://crbug.com/724471  V8InProcessShutdownWithHungRequest flaky on a cronet
bot

Original issue's description:
> Allow use of Mojo/V8 ProxyResolvers with URLRequestContextBuilder.
> 
> This adds URLRequestContextBuilderV8, which can construct a
> URLRequestContext using either type of ProxyResolver. When using such
> a resolver, the ProxyService will fetch requests using the
> URLRequestContext that was created with the builder.
> 
> Added a subclass instead of modifying URLRequestContextBuilder so it
> can continue to be used without depending on V8.
> 
> BUG=717253
> 
> Review-Url: https://codereview.chromium.org/2881613002
> Cr-Commit-Position: refs/heads/master@{#472439}
> Committed:
https://chromium.googlesource.com/chromium/src/+/f4fc1f04fe1a0d835a508720fdd9...

TBR=eroman@chromium.org,mmenke@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=717253

Review-Url: https://codereview.chromium.org/2888043008
Cr-Commit-Position: refs/heads/master@{#473182}
Committed:
https://chromium.googlesource.com/chromium/src/+/b7060318b0cc8ccf7f4572104d08...
==========

[commit-bot: I haz the power, 2017-05-19 14:41:32]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/b7060318b0cc8ccf7f4572104d08...