Add blink::ServiceRegistry and expose it from LocalFrame and Platform.

third_party/WebKit/Source/modules/battery/BatteryDispatcher.cpp

Index: third_party/WebKit/Source/modules/battery/BatteryDispatcher.cpp
diff --git a/third_party/WebKit/Source/modules/battery/BatteryDispatcher.cpp b/third_party/WebKit/Source/modules/battery/BatteryDispatcher.cpp
index 21d167cc1d396659f8aa7a78b57d6e69bb247d9f..667e7f5e0b19b528d10be3c214d9e195741921b2 100644
--- a/third_party/WebKit/Source/modules/battery/BatteryDispatcher.cpp
+++ b/third_party/WebKit/Source/modules/battery/BatteryDispatcher.cpp
@@ -6,6 +6,7 @@
 
 #include "platform/threading/BindForMojo.h"
 #include "public/platform/Platform.h"
+#include "public/platform/ServiceRegistry.h"
 #include "wtf/Assertions.h"
 #include "wtf/PassOwnPtr.h"
 
@@ -53,7 +54,11 @@ void BatteryDispatcher::updateBatteryStatus(const BatteryStatus& batteryStatus)
 void BatteryDispatcher::startListening()
 {
     ASSERT(!m_monitor.is_bound());
-    Platform::current()->connectToRemoteService(mojo::GetProxy(&m_monitor));
+    if (!Platform::current()->serviceRegistry())

[esprehn, 2016/03/31 05:10:43]

So one thing we could do is have a static EmptyServiceRegistry and make platform
return that by default. Then you're assured it's never null.

[Sam McNally, 2016/03/31 09:26:27]

Done.

+        return;
+
+    Platform::current()->serviceRegistry()->connectToRemoteService(
+        mojo::GetProxy(&m_monitor));
     // m_monitor can be null during testing.
     if (m_monitor)
         queryNextStatus();