android_webview: force clang for host targets.

android_webview: force clang for host targets.

Current AOSP versions use clang to build host code by default and
https://codereview.chromium.org/516723004 configured common.gypi to
assume this, but this breaks building against older releases where clang
is not the default. Force use of clang by emitting "LOCAL_CLANG := true"
into generated host makefiles so that it will work no matter what
release we are using.

BUG=421873
Committed: https://crrev.com/981f132f9f354a9c3cd1bb45bb1f95f8d006f5fa
Cr-Commit-Position: refs/heads/master@{#298942}

[Torne, 2014-10-09 14:10:38]

torne@chromium.org changed reviewers:
+ primiano@chromium.org

[Primiano Tucci (use gerrit), 2014-10-09 14:18:12]

LGTM

https://codereview.chromium.org/644683004/diff/1/build/common.gypi
File build/common.gypi (right):

https://codereview.chromium.org/644683004/diff/1/build/common.gypi#newcode5586
build/common.gypi:5586: ['android_webview_build==1', {
Shouldn't this be
android_webview_build==1 and host_clang==1 
just in case chromium goes back on his footsteps at some point?

[Torne, 2014-10-09 14:21:54]

On 2014/10/09 14:18:12, Primiano Tucci wrote:
> LGTM
> 
> https://codereview.chromium.org/644683004/diff/1/build/common.gypi
> File build/common.gypi (right):
> 
> https://codereview.chromium.org/644683004/diff/1/build/common.gypi#newcode5586
> build/common.gypi:5586: ['android_webview_build==1', {
> Shouldn't this be
> android_webview_build==1 and host_clang==1 
> just in case chromium goes back on his footsteps at some point?

We can't go back to not using clang on host, because the codebase is adopting
C++11 features that will just not compile at all in the mac's gcc 4.2. So we're
stuck like this. :)

[Torne, 2014-10-09 14:32:44]

The CQ bit was checked by torne@chromium.org

[commit-bot: I haz the power, 2014-10-09 14:33:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/644683004/1

[commit-bot: I haz the power, 2014-10-09 18:37:33]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-09 18:38:11]

Patchset 1 (id:??) landed as
https://crrev.com/981f132f9f354a9c3cd1bb45bb1f95f8d006f5fa
Cr-Commit-Position: refs/heads/master@{#298942}