Update V8 DEPS.

Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/6167734..9c1e28b

Rolling v8/tools/clang: https://chromium.googlesource.com/chromium/src/tools/clang/+log/bd3b137..8427dae

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

Change-Id: Id8b75c73794c8d13dce3322a49d9259d02529ee4
Reviewed-on: https://chromium-review.googlesource.com/784472Reviewed-by: v8 autoroll <v8-autoroll@chromium.org>
Commit-Queue: v8 autoroll <v8-autoroll@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49559}

DEPS

@@ -9,7 +9,7 @@ vars = {
 
 deps = {
   'v8/build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '6167734e03a9644bf0f9f3c8ca1f516659d311ae',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + '9c1e28b9fdbe4c1563a20dc22f1441b9d860d936',
   'v8/tools/gyp':
     Var('chromium_url') + '/external/gyp.git' + '@' + 'd61a9397e668fa9843c4aa7da9e79460fe590bfb',
   'v8/third_party/icu':
@@ -51,7 +51,7 @@ deps = {
   'v8/test/test262/harness':
     Var('chromium_url') + '/external/github.com/test262-utils/test262-harness-py.git' + '@' + '0f2acdd882c84cff43b9d60df7574a1901e2cdcd',
   'v8/tools/clang':
-    Var('chromium_url') + '/chromium/src/tools/clang.git' + '@' + 'bd3b1379906835817709475b687b811533c01f23',
+    Var('chromium_url') + '/chromium/src/tools/clang.git' + '@' + '8427dae2b5a769314af722e09000563b5184ba06',
   'v8/tools/luci-go':
     Var('chromium_url') + '/chromium/src/tools/luci-go.git' + '@' + '45a8a51fda92e123619a69e7644d9c64a320b0c1',
   'v8/test/wasm-js':