add libaom to src/third_party

Enabling the checkout requires setting
    "custom_vars": {
      "checkout_libaom": True,
    },

in .gclient solutions[]

BUG=aomedia:937

Change-Id: I70e4e847a16155080016d090f8bca293e871a225
Reviewed-on: https://chromium-review.googlesource.com/726469
Commit-Queue: Johann Koenig <[email protected]>
Reviewed-by: Dirk Pranke <[email protected]>
Reviewed-by: Brett Wilson <[email protected]>
Reviewed-by: Tom Finegan <[email protected]>
Reviewed-by: Dale Curtis <[email protected]>
Reviewed-by: Chris Palmer <[email protected]>
Reviewed-by: Martin Barbella <[email protected]>
Cr-Commit-Position: refs/heads/master@{#512670}
diff --git a/DEPS b/DEPS
index 4e82354..7bd66cd95 100644
--- a/DEPS
+++ b/DEPS
@@ -38,10 +38,14 @@
   # custom_vars.
   'checkout_src_internal': False,
 
+  # libaom provides support for AV1 but the bitstream is not frozen.
+  'checkout_libaom': False,
+
   # TODO(dpranke): change to != "small" once != is supported.
   'checkout_traffic_annotation_tools': 'checkout_configuration == "default"',
   'checkout_instrumented_libraries': 'checkout_linux and checkout_configuration == "default"',
 
+  'aomedia_git': 'https://aomedia.googlesource.com',
   'chromium_git': 'https://chromium.googlesource.com',
   'swiftshader_git': 'https://swiftshader.googlesource.com',
   'pdfium_git': 'https://pdfium.googlesource.com',
@@ -130,6 +134,7 @@
 # If you need to add a new host, contact chrome infrastracture team.
 allowed_hosts = [
   'android.googlesource.com',
+  'aomedia.googlesource.com',
   'boringssl.googlesource.com',
   'chrome-internal.googlesource.com',
   'chromium.googlesource.com',
@@ -394,6 +399,11 @@
   'src/third_party/libaddressinput/src':
     Var('chromium_git') + '/external/libaddressinput.git' + '@' + '8200a3221282582ca3291ef219257ca4be7426ca',
 
+  'src/third_party/libaom/source/libaom': {
+    'url': Var('aomedia_git') + '/aom.git' + '@' +  'd9f2286e4c0bbb0fee5719d151653247939c3847',
+    'condition': 'checkout_libaom',
+  },
+
   # Userspace interface to kernel DRM services.
   'src/third_party/libdrm/src': {
       'url': Var('chromium_git') + '/chromiumos/third_party/libdrm.git' + '@' + '0ce18bedd3e62d4784fa755403801934ba171084',