Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/1a0ce50..a5cd715

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/db1e69e..83bd7f4

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

Change-Id: Iab28e206e9aa2b0376185abb1edb0d9fc4948a3f
Reviewed-on: https://chromium-review.googlesource.com/c/1273255
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@{#56511}

DEPS

@@ -13,9 +13,9 @@ vars = {
 
 deps = {
   'v8/build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '1a0ce5087e25809c43a0add52ef5f00fbfcb149d',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + 'a5cd715c0df741db5124ffba0cb4640f3d0633bb',
   'v8/third_party/depot_tools':
-    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + 'db1e69ef0345752628872b7ff38a79240fa57201',
+    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '83bd7f4cd5fa45c7b2b8a9187d3c3d3c13525621',
   'v8/third_party/icu':
     Var('chromium_url') + '/chromium/deps/icu.git' + '@' + 'ccad4472126e35ccd1d19bea38b6675802d40472',
   'v8/third_party/instrumented_libraries':