Reformat all gn files in /google_apis/gcm.

`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=peter@chromium.org

Bug: 1041419
Change-Id: Ifbfdf736ebe87daf84c9a96dfe98251b7bd81a65
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1998145
Auto-Submit: Nico Weber <thakis@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#730770}

google_apis/gcm/BUILD.gn

@@ -104,9 +104,7 @@ static_library("test_support") {
     "monitoring/fake_gcm_stats_recorder.h",
   ]
 
-  public_deps = [
-    ":gcm",
-  ]
+  public_deps = [ ":gcm" ]
   deps = [
     "//base",
     "//mojo/public/cpp/system:system",
@@ -120,9 +118,7 @@ static_library("test_support") {
 if (!is_ios) {
   executable("mcs_probe") {
     testonly = true
-    sources = [
-      "tools/mcs_probe.cc",
-    ]
+    sources = [ "tools/mcs_probe.cc" ]
 
     deps = [
       ":gcm",