Add missing viz dep to weblayer_browsertests

Without this GPU process chain crashes trying to load ExternalBeginFrameSourceAndroid.

Change-Id: I011bdd517167e622d04ba9e65f8bd7d283811b32
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1942338
Auto-Submit: Alex Clarke <alexclarke@chromium.org>
Commit-Queue: Tim Volodine <timvolodine@chromium.org>
Reviewed-by: Tim Volodine <timvolodine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719989}

weblayer/test/BUILD.gn

@@ -118,6 +118,7 @@ test("weblayer_browsertests") {
       "//android_webview:generate_aw_strings_grit",
       "//android_webview:locale_pak_assets",
       "//android_webview:pak_file_assets",
+      "//components/viz/service:service_java",
       "//content/public/test/android:android_test_message_pump_support_java",
       "//content/test:android_test_message_pump_support",
       "//content/test:android_test_message_pump_support",