[win] Enable ModuleDatabase behind a flag.

chrome/browser/chrome_browser_main_win.h

Index: chrome/browser/chrome_browser_main_win.h
diff --git a/chrome/browser/chrome_browser_main_win.h b/chrome/browser/chrome_browser_main_win.h
index 35165b002fb192f1ec1b768abb92472089dd679b..68ad182f70c81f97b1f5602ebf1d64778019d545 100644
--- a/chrome/browser/chrome_browser_main_win.h
+++ b/chrome/browser/chrome_browser_main_win.h
@@ -13,6 +13,7 @@
 #include "third_party/kasko/kasko_features.h"
 
 class DidRunUpdater;
+class ModuleWatcher;
 
 namespace base {
 class CommandLine;
@@ -78,6 +79,8 @@ class ChromeBrowserMainPartsWin : public ChromeBrowserMainParts {
   base::FilePathWatcher failed_kasko_crash_report_watcher_;
 #endif
 
+  std::unique_ptr<ModuleWatcher> module_watcher_;
+
   DISALLOW_COPY_AND_ASSIGN(ChromeBrowserMainPartsWin);
 };