Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/46adc39..dc0b854

Rolling v8/third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/364205c..81098e5

TBR=machenbach@chromium.org,tmrts@chromium.org,v8-waterfall-sheriff@grotations.appspotmail.com

Change-Id: Ic95d3b8d0d4265a2f43f6434469e9e65601da52a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2610430Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#71906}

DEPS

@@ -88,9 +88,9 @@ vars = {
 
 deps = {
   'build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '46adc39ea771b7613e422b6c9ade554e75972b65',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + 'dc0b854645847007ec570f6a5c7e0b937b88b84b',
   'third_party/depot_tools':
-    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '364205c70ed16c00802b1c264e88d8e03a0b37ae',
+    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '81098e59adfcb81e94b0f8584f5bdbfdb0554573',
   'third_party/icu':
     Var('chromium_url') + '/chromium/deps/icu.git' + '@' + '899e18383fd732b47e6978db2b960a1b2a80179b',
   'third_party/instrumented_libraries':