Build Cronet for iOS with bitcode enabled

Build Cronet for iOS with bitcode enabled

BUG=723816
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester

[kapishnikov, 2017-05-18 03:52:01]

Description was changed from

==========
Build Cronet for iOS with bitcode enabled

BUG=723816
==========

to

==========
Build Cronet for iOS with bitcode enabled

BUG=723816
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester
==========

[kapishnikov, 2017-05-18 03:53:15]

The CQ bit was checked by kapishnikov@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-18 03:54:15]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[kapishnikov, 2017-05-18 03:55:28]

kapishnikov@chromium.org changed reviewers:
+ lilyhoughton@chromium.org, mef@chromium.org

[kapishnikov, 2017-05-18 03:55:29]

PTAL. Tested it with a sample Xcode project that was build with bitcode enabled
and thus required that all embedded frameworks were also built with bitcode
enabled.

[commit-bot: I haz the power, 2017-05-18 04:32:37]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-18 04:32:37]

Dry run: This issue passed the CQ dry run.

[mef, 2017-05-18 14:09:03]

On 2017/05/18 03:55:29, kapishnikov wrote:
> PTAL. Tested it with a sample Xcode project that was build with bitcode
enabled
> and thus required that all embedded frameworks were also built with bitcode
> enabled.

Cool, thanks for trying this out! A couple of questions:

- How does it affect the binary size of device release framework binaries?
- Does it do the right thing for simulator and/or debug builds?

[kapishnikov, 2017-05-19 19:23:28]

I have updated the linked bug with more info.

On 2017/05/18 14:09:03, mef wrote:
> On 2017/05/18 03:55:29, kapishnikov wrote:
> > PTAL. Tested it with a sample Xcode project that was build with bitcode
> enabled
> > and thus required that all embedded frameworks were also built with bitcode
> > enabled.
> 
> Cool, thanks for trying this out! A couple of questions:
> 
> - How does it affect the binary size of device release framework binaries?
The intermediate binary size increased very significantly from 6MB to 1.2GB. If
an embedding app is not built with bitcode enabled, the size goes back to 6MB
since the bitcode is automatically stripped out. We don't know what the size
would be if the app with bitcode is submitted to the appstore and recompiled by
Apple.

> - Does it do the right thing for simulator and/or debug builds?
It doesn't include bitcode in debug since it only makes sense when the app is
submitted to the appstore (which supposed to be a release version). However, it
may complicate the development process a little bit, since the developer will
need to change the project settings before creating the release version.

The simulator version is built without bitcode. That is correct since bitcode
can only be added for ARM.