Add mojo::StrongBindingSet and use it in GeolocationServiceContext.

content/browser/devtools/protocol/emulation_handler.cc

Index: content/browser/devtools/protocol/emulation_handler.cc
diff --git a/content/browser/devtools/protocol/emulation_handler.cc b/content/browser/devtools/protocol/emulation_handler.cc
index cae9f00fc490b8beb25ea41dafc8dfbcead61daa..c75d9c2bf08e19d25f7186a36cedc8e0aff24ed8 100644
--- a/content/browser/devtools/protocol/emulation_handler.cc
+++ b/content/browser/devtools/protocol/emulation_handler.cc
@@ -10,6 +10,7 @@
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/common/view_messages.h"
+#include "content/public/common/geoposition.h"
 #include "content/public/common/url_constants.h"
 
 namespace content {
@@ -75,7 +76,7 @@ Response EmulationHandler::SetGeolocationOverride(
     return Response::InternalError("Could not connect to view");
 
   GeolocationServiceContext* geolocation_context =
-      GetWebContents()->GetGeolocationServiceContext();
+      GeolocationServiceContext::GetOrCreateForWebContents(GetWebContents());
   scoped_ptr<Geoposition> geoposition(new Geoposition());
   if (latitude && longitude && accuracy) {
     geoposition->latitude = *latitude;
@@ -97,8 +98,9 @@ Response EmulationHandler::ClearGeolocationOverride() {
     return Response::InternalError("Could not connect to view");
 
   GeolocationServiceContext* geolocation_context =
-      GetWebContents()->GetGeolocationServiceContext();
-  geolocation_context->ClearOverride();
+      GeolocationServiceContext::FromWebContents(GetWebContents());
+  if (geolocation_context)
+    geolocation_context->ClearOverride();
   return Response::OK();

[Michael van Ouwerkerk, 2015/11/11 11:20:56]

Should this return OK if !geolocation_context ?

[Sam McNally, 2015/11/13 00:49:59]

Yes. If an EmulationHandler tries to clear the override without either there
being a service created or an override set, then this should be a no-op, so OK
is correct.

 }