Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/b376554..ce6d3d8

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

Change-Id: Idda412143f1ff00ca10e8822acb5a0754372ee29
Reviewed-on: https://chromium-review.googlesource.com/694681Reviewed-by: v8 autoroll <v8-autoroll@chromium.org>
Commit-Queue: v8 autoroll <v8-autoroll@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48251}

DEPS

@@ -8,7 +8,7 @@ vars = {
 
 deps = {
   "v8/build":
-    Var("chromium_url") + "/chromium/src/build.git" + "@" + "b3765543a0e439f71548f86a783a399e0c121a4f",
+    Var("chromium_url") + "/chromium/src/build.git" + "@" + "ce6d3d886885f095c753819b7693c65d999e8b4b",
   "v8/tools/gyp":
     Var("chromium_url") + "/external/gyp.git" + "@" + "d61a9397e668fa9843c4aa7da9e79460fe590bfb",
   "v8/third_party/icu":