[Notification] Make HTML5 Notification use ActionCenter on Windows 10, behind Flags.

chrome/browser/browser_process_impl.cc

Index: chrome/browser/browser_process_impl.cc
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index 562caa37b40cea749da981a142207c35b8426579..c9d626b783a5870572606c3ca5ee7522e5b8b1ac 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -311,6 +311,11 @@ void BrowserProcessImpl::StartTearDown() {
   plugins_resource_service_.reset();
 #endif
 
+  // Clear notification bridge explicitly, since it may consume resources for
+  // notifications that haven't been shown. For example, on Windows 10 we'd use
+  // store temporary images files.
+  notification_bridge_.reset();
+
   // Need to clear the desktop notification balloons before the io_thread_ and
   // before the profiles, since if there are any still showing we will access
   // those things during teardown.