Roll recipe dependencies (trivial).

This is an automated CL created by the recipe roller. This CL rolls recipe
changes from upstream projects (e.g. depot_tools) into downstream projects
(e.g. tools/build).

More info is at https://goo.gl/zkKdpD. Use https://goo.gl/noib3a to file a bug
(or complain)

build:
  https://crrev.com/a2b056bd69e365ff4c2a9bfa961ad8e13565470f Archiving of AppRTC APK in client.webrtc waterfall (ehmaldonado@chromium.org)
  https://crrev.com/2dd50f3f904647f20ed62fdb3561543d5f1f0a73 WebRTC: Add android swarming bots. (ehmaldonado@chromium.org)

TBR=martiniss@chromium.org,phajdan.jr@chromium.org
BUG=583318,647242

Recipe-Tryjob-Bypass-Reason: Autoroller
Bugdroid-Send-Email: False
Review-Url: https://codereview.chromium.org/2354533002
Cr-Commit-Position: refs/heads/master@{#419441}

infra/config/recipes.cfg

@@ -5,7 +5,7 @@ deps {
   project_id: "build"
   url: "https://chromium.googlesource.com/chromium/tools/build.git"
   branch: "master"
-  revision: "1a9a50a459c9e3c081719d3e835cac213c319136"
+  revision: "2dd50f3f904647f20ed62fdb3561543d5f1f0a73"
 }
 deps {
   project_id: "depot_tools"