Pass corresponding C/C++ flags to ObjC/C++

Pass corresponding C/C++ flags to ObjC/C++

A GN change for precompiled headers meant that cflags_c aren't passed automaticall to the Objective C compiler, and cflags_cc aren't passed to the Objective C++ compiler.

Copies the c/cc flags over to the objc/objcc variables in the compiler setup.

TBR=dpranke@chromium.org
BUG=511323
Committed: https://crrev.com/839f4802a610edc83e5c6bd9c178208b3715324c
Cr-Commit-Position: refs/heads/master@{#339348}

[brettw, 2015-07-17 21:18:15]

The CQ bit was checked by brettw@chromium.org

[commit-bot: I haz the power, 2015-07-17 21:19:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1233683003/1

[Dirk Pranke, 2015-07-17 21:41:53]

lgtm

[brettw, 2015-07-17 22:40:28]

The CQ bit was unchecked by brettw@chromium.org

[brettw, 2015-07-17 22:40:34]

The CQ bit was checked by brettw@chromium.org

[commit-bot: I haz the power, 2015-07-17 22:40:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1233683003/1

[commit-bot: I haz the power, 2015-07-17 22:51:30]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-17 22:52:19]

Patchset 1 (id:??) landed as
https://crrev.com/839f4802a610edc83e5c6bd9c178208b3715324c
Cr-Commit-Position: refs/heads/master@{#339348}