[DIAL API] Force increment registry generation on discoverNow.

chrome/browser/extensions/api/dial/dial_registry.cc

Index: chrome/browser/extensions/api/dial/dial_registry.cc
diff --git a/chrome/browser/extensions/api/dial/dial_registry.cc b/chrome/browser/extensions/api/dial/dial_registry.cc
index 45a7400b1122a1c87a91169e662d09ed3be7ac8d..ab0b2a1fe6d2b53090a76c23dcebd1bb27d2fe52 100644
--- a/chrome/browser/extensions/api/dial/dial_registry.cc
+++ b/chrome/browser/extensions/api/dial/dial_registry.cc
@@ -106,7 +106,14 @@ bool DialRegistry::DiscoverNow() {
 
   if (!dial_->HasObserver(this))
     NOTREACHED() << "DiscoverNow() called without observing dial_";
-  return dial_->Discover();
+
+  // Force increment |registry_generation_| to ensure an event is sent even if
+  // the device list did not change.
+  bool started = dial_->Discover();
+  if (started)
+    ++registry_generation_;
+
+  return started;
 }
 
 void DialRegistry::StartPeriodicDiscovery() {