linux_aura: Attempt to green the official builder by reverting unwind support.

This effectively reverts in r243919 and r244331 in a desperate attempt
to fix the tree.

Build fail output:

FAILED: cd ../../chrome; flock -- /tmp/linux_package_lock bash ../out/Release/installer/rpm/build.sh -o../out/Release -b ../out/Release -a ia32 -c beta
Staging common install files in '/tmp/rpm.build.XtJRbJ'...
eu-strip: while computing checksum for debug information: Invalid argument
FAILED: cd ../../chrome; flock -- /tmp/linux_package_lock bash ../out/Release/installer/rpm/build.sh -o../out/Release -b ../out/Release -a ia32 -c unstable
Staging common install files in '/tmp/rpm.build.t4jNp4'...
eu-strip: while computing checksum for debug information: Invalid argument
FAILED: cd ../../chrome; flock -- /tmp/linux_package_lock bash ../out/Release/installer/debian/build.sh -o../out/Release -b ../out/Release -a ia32 -c unstable
Staging common install files in '/tmp/deb.build.CxnH9l'...
eu-strip: while computing checksum for debug information: Invalid argument
Cleaning...
FAILED: cd ../../chrome; flock -- /tmp/linux_package_lock bash ../out/Release/installer/debian/build.sh -o../out/Release -b ../out/Release -a ia32 -c stable
Staging common install files in '/tmp/deb.build.9Zyie1'...
eu-strip: while computing checksum for debug information: Invalid argument
Cleaning...
FAILED: cd ../../chrome; flock -- /tmp/linux_package_lock bash ../out/Release/installer/debian/build.sh -o../out/Release -b ../out/Release -a ia32 -c beta
Staging common install files in '/tmp/deb.build.xUB39X'...
eu-strip: while computing checksum for debug information: Invalid argument
Cleaning...
FAILED: cd ../../chrome; flock -- /tmp/linux_package_lock bash ../out/Release/installer/rpm/build.sh -o../out/Release -b ../out/Release -a ia32 -c stable
Staging common install files in '/tmp/rpm.build.aN0PGV'...
eu-strip: while computing checksum for debug information: Invalid argument
../out/Release/chrome, section '.eh_frame': the call frame entry at offset 0x18 uses a DWARF expression to describe how to recover register '.cfa',  but this translator cannot yet translate DWARF expressions to Breakpad postfix expressions
ninja: build stopped: subcommand failed.

BUG=180975
TBR=spang@chromium.org, stip@chromium.org

Review URL: https://codereview.chromium.org/141013009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245421 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245421