Implement window management devtools commands for headless.

headless/lib/browser/headless_devtools_client_impl.cc

Index: headless/lib/browser/headless_devtools_client_impl.cc
diff --git a/headless/lib/browser/headless_devtools_client_impl.cc b/headless/lib/browser/headless_devtools_client_impl.cc
index 0b6cc96930c91e1403d250aee160b6ade95d5428..2243b20b07ab39dd09016f8c036458df67f109b7 100644
--- a/headless/lib/browser/headless_devtools_client_impl.cc
+++ b/headless/lib/browser/headless_devtools_client_impl.cc
@@ -38,6 +38,7 @@ HeadlessDevToolsClientImpl::HeadlessDevToolsClientImpl()
       accessibility_domain_(this),
       animation_domain_(this),
       application_cache_domain_(this),
+      browser_domain_(this),
       cache_storage_domain_(this),
       console_domain_(this),
       css_domain_(this),
@@ -244,6 +245,10 @@ application_cache::Domain* HeadlessDevToolsClientImpl::GetApplicationCache() {
   return &application_cache_domain_;
 }
 
+browser::Domain* HeadlessDevToolsClientImpl::GetBrowser() {
+  return &browser_domain_;
+}
+
 cache_storage::Domain* HeadlessDevToolsClientImpl::GetCacheStorage() {
   return &cache_storage_domain_;
 }