Enhance chrome.app.window API with title property

extensions/browser/app_window/app_window.cc

Index: extensions/browser/app_window/app_window.cc
diff --git a/extensions/browser/app_window/app_window.cc b/extensions/browser/app_window/app_window.cc
index cee54392ed9a1b388eb6518cebe6e478106169bd..a9877fbfbc419e04c2d3a054a0a588360f3559cc 100644
--- a/extensions/browser/app_window/app_window.cc
+++ b/extensions/browser/app_window/app_window.cc
@@ -300,6 +300,7 @@ void AppWindow::Init(const GURL& url,
   is_ime_window_ = params.is_ime_window;
   show_in_shelf_ = params.show_in_shelf;
   window_icon_url_ = params.window_icon_url;
+  title_ = params.title;
 
   AppWindowClient* app_window_client = AppWindowClient::Get();
   native_app_window_.reset(
@@ -588,7 +589,11 @@ base::string16 AppWindow::GetTitle() const {
   content::NavigationEntry* entry = web_contents() ?
       web_contents()->GetController().GetLastCommittedEntry() : nullptr;
   if (!entry || entry->GetTitle().empty()) {
-    title = base::UTF8ToUTF16(extension->name());
+    if (!title_.empty()) {
+      title = base::UTF8ToUTF16(title_);
+    } else {
+      title = base::UTF8ToUTF16(extension->name());
+    }
   } else {
     title = web_contents()->GetTitle();
   }