Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/d602f57..e1a9ece

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

Change-Id: I498c812dae9ab432ceadfdd512088c8d2a85a7a6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2280455Reviewed-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@{#68681}

DEPS

@@ -80,7 +80,7 @@ vars = {
 
 deps = {
   'v8/build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + 'd602f57725bc5e7394b8a012757a082f081321be',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + 'e1a9ece0a3dd55758e471088ecd6c8937808ffe6',
   'v8/third_party/depot_tools':
     Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '95099f475463caa66801dd1b22ee851fe8bc05be',
   'v8/third_party/icu':