Android: use gcc (not cpp) to preprocess templates.

Android: use gcc (not cpp) to preprocess templates.

When building the WebView on macs, cpp is a wrapper script around llvm
which does not accept all the same arguments as the cpp that's part of
gcc. Invoke gcc -E instead, which should be guaranteed to accept gcc
arguments (even if it ultimately invokes llvm as well).

BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=186439

[Torne, 2013-03-06 11:35:30]

Hi Marcus,

Rather than try to invoke the target cpp (which I can't work out how to do
cleanly), I'm just using gcc -E, which seems to work on mac as "gcc" points to
something that really does understand gcc arguments (cpp is a gross shell script
that actually tries to parse the args before running llvm). I've tested that
this doesn't make any difference on linux hosts.

[bulach, 2013-03-06 15:05:17]

lgtm, seems fine by me and the bots look healthy, thanks!

[Torne, 2013-03-06 15:11:47]

Committed patchset #1 manually as r186439 (presubmit successful).