Remove ninja special cases for iOS build configurations.
Gyp now sets -iphoneos architecture, so armv7 switching isn't required in
common.gypi. This CL also gets rid of ONLY_ACTIVE_ARCH, which requires full
rebuilds when switching devices between armv7, armv7s and arm64 devices.
Also remove the iOS5 arclite link step, which isn't needed in iOS6+.
BUG=312300
TEST=ios_rel_device builds
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=231456
NOTRY=true
Review URL: https://codereview.chromium.org/
25535004
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231658 0039d316-1c4b-4281-b951-d872f2087c98