Reformat all gn files in /testing/iossim.

`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=rohitrao@chromium.org

Bug: 1041419
Change-Id: I56d2b632cd9e44db7c184e96bf119392e421405b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1998571
Auto-Submit: Nico Weber <thakis@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731561}

testing/iossim/BUILD.gn

@@ -6,21 +6,14 @@ import("//build/config/mac/mac_sdk.gni")
 
 if (current_toolchain == host_toolchain) {
   executable("iossim") {
-    sources = [
-      "iossim.mm",
-    ]
+    sources = [ "iossim.mm" ]
     libs = [ "Foundation.framework" ]
   }
 } else if (current_toolchain == default_toolchain) {
   copy("iossim") {
-    deps = [
-      ":iossim($host_toolchain)",
-    ]
-    outputs = [
-      "$root_out_dir/iossim",
-    ]
-    sources = [
-      get_label_info(":iossim($host_toolchain)", "root_out_dir") + "/iossim",
-    ]
+    deps = [ ":iossim($host_toolchain)" ]
+    outputs = [ "$root_out_dir/iossim" ]
+    sources = [ get_label_info(":iossim($host_toolchain)", "root_out_dir") +
+                "/iossim" ]
   }
 }