Adding missing manifests to gn-built bro.exe

Many executables are missing embedded manifest files when built with gn.
This causes OS compatibility information to be omitted which can lead
to strange behavior. This adds a manifest to bro.exe.

BUG=602505

Review-Url: https://codereview.chromium.org/2028743002
Cr-Commit-Position: refs/heads/master@{#397044}

third_party/brotli/BUILD.gn

@@ -88,6 +88,7 @@ if (current_toolchain == host_toolchain) {
     deps = [
       ":brotli",
       "//build/config/sanitizers:deps",
+      "//build/win:default_exe_manifest",
     ]
 
     if (is_win && visual_studio_version == "2015") {