Reformat all gn files in /third_party/blink/renderer/build.

`gn format` recently changed its formatting behavior
for deps, source, and a few other elements when they
are assigned (with =) single-element lists to be consistent
with the formatting of updates (with +=) with single-element.

Now that we've rolled in a GN binary with the change,
reformat all files so that people don't get presubmit
warnings due to this.

This CL was uploaded by git cl split.

R=rnk@chromium.org

Bug: 1041419
Change-Id: Ib2955e96e7cb286e0b17b172a15b8228936cb5d9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1997806
Auto-Submit: Nico Weber <thakis@chromium.org>
Reviewed-by: Reid Kleckner <rnk@chromium.org>
Commit-Queue: Reid Kleckner <rnk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#730911}

third_party/blink/renderer/build/scripts/scripts.gni

@@ -93,9 +93,7 @@ make_core_generated_deps = [
 template("blink_python_runner") {
   action(target_name) {
     script = "$_scripts_dir/run_with_pythonpath.py"
-    sources = [
-      invoker.script,
-    ]
+    sources = [ invoker.script ]
     if (defined(invoker.sources)) {
       sources += invoker.sources
     }