Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/425295f..c55a0b9

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/2b71832..cb629a4

TBR=machenbach@chromium.org,hablich@chromium.org,sergiyb@chromium.org

Change-Id: I10387d35ae298c7d20bc5eacfb70cff05ecd4052
Reviewed-on: https://chromium-review.googlesource.com/c/1304193
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#57051}

DEPS

@@ -13,9 +13,9 @@ vars = {
 
 deps = {
   'v8/build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '425295f6cff0b886e0b7c982e63265e91778b962',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + 'c55a0b9f680eb777534848fe3fb306bbdc7a7a05',
   'v8/third_party/depot_tools':
-    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '2b71832f6d8dc74119589992836cf95aeb8a9842',
+    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + 'cb629a482b3d3c13e46a66031ba4c0cc3679d200',
   'v8/third_party/icu':
     Var('chromium_url') + '/chromium/deps/icu.git' + '@' + 'b029971f1fc6b20d06887c47c7afebd5881f31ff',
   'v8/third_party/instrumented_libraries':