Revert of Roll libvpx 269083:275816 webrtc 6352:6415 (https://codereview.chromium.org/299313003/)

Reason for revert:
Broke compile step on http://build.chromium.org/p/chromium.linux/builders/Android%20Webview%20AOSP%20Builder/builds/12011

Compile error message:

Export includes file: external/chromium_org/GypAndroid.linux-arm.mk -- out/target/product/generic/obj/STATIC_LIBRARIES/third_party_webrtc_modules_PCM16B_gyp_intermediates/export_includes
make: *** No rule to make target `/mnt/data/b/build/slave/Android_Webview_AOSP_Builder/build/android-src/out/target/product/generic/obj/STATIC_LIBRARIES/libvpx_asm_offsets_vp8_intermediates/libvpx_asm_offsets_vp8.a', needed by `out/target/product/generic/obj/GYP/third_party_libvpx_gen_asm_offsets_vp8_gyp_intermediates/vp8_asm_enc_offsets.o'.  Stop.


Original issue's description:
> Roll libvpx 269083:275816 webrtc 6352:6415
> 
> libvpx:
> See https://codereview.chromium.org/295313002/
> https://codereview.chromium.org/298063002/
> https://codereview.chromium.org/305533008/
> https://codereview.chromium.org/305703002/
> https://codereview.chromium.org/298383003/
> https://codereview.chromium.org/302863004/
> https://codereview.chromium.org/320923003/
> for the actual changes.
> 
> webrtc:
> See https://codereview.chromium.org/313243004/
> for the actual changes.
> 
> BUG=377062
> R=ajm@chromium.org, tomfinegan@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=276820

TBR=fgalligan
NOTRY=true

Review URL: https://codereview.chromium.org/330193002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276832 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -41,7 +41,7 @@ vars = {
   "google_toolbox_for_mac_revision": "662",
   "libaddressinput_revision": "273",
   "libphonenumber_revision": "621",
-  "libvpx_revision": "275816",
+  "libvpx_revision": "269083",
   "lss_revision": "26",
   "sfntly_revision": "239",
   "lighttpd_revision": "33737",
@@ -54,7 +54,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling WebRTC
   # and V8 without interference from each other.
-  "webrtc_revision": "6415",
+  "webrtc_revision": "6413",
   "jsoncpp_revision": "248",
   "nss_revision": "275589",
   # Three lines of non-changing comments so that