Workaround assembly offsets build error for WebRTC standalone.

This enables the new build WebRTC is moving to as a result of
the Chromium Git switch in https://webrtc-codereview.appspot.com/16229005/

Without this compilation fails like this (manually linewrapped):

[209/2563] ACTION gen_asm_offsets_vp8: unpack_lib_posix_655f0f79285c2909a9158512344a42a2
FAILED: cd ../../chromium/src/third_party/libvpx;
../../../../third_party/libvpx/unpack_lib_posix.sh
-d ../../../../out/Release/obj/chromium/src/third_party/libvpx/gen_asm_offsets_vp8.gen
-f vp8_asm_enc_offsets.o
-a ../../../../out/Release/libvpx_asm_offsets_vp8.a
-a ../../../../out/Release/obj/third_party/libvpx/libvpx_asm_offsets_vp8.a
-a ../../../../out/Release/obj/Source/WebKit/chromium/third_party/libvpx/libvpx_asm_offsets_vp8.a
-a ""
Failed to locate a static library.

In the current setup, the static library files are put in
<(LIB_DIR)/third_party/libvpx
but after https://webrtc-codereview.appspot.com/16229005/ they
end up in <(LIB_DIR)/chromium/src/third_party/libvpx instead
(caused by the fact that we're now symlinking into Chromium's libvpx
folder instead).

I assume adding another line to fix our problem won't cause any side-effects?

BUG=webrtc:2863, chromium:339647
TEST=Passing local build with https://webrtc-codereview.appspot.com/16229005/ and this patch applied.
R=tomfinegan@chromium.org

Review URL: https://codereview.chromium.org/450993002

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/libvpx@288724 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
1 file changed