content: convert zoom notifications to observer usage

content/browser/host_zoom_map_impl.cc

Index: content/browser/host_zoom_map_impl.cc
diff --git a/content/browser/host_zoom_map_impl.cc b/content/browser/host_zoom_map_impl.cc
index 942d6f49c61064c6e06e4d6ff73c30e77ad77360..bd4304cadae1fff1cb3241fac664fc43247ceeb9 100644
--- a/content/browser/host_zoom_map_impl.cc
+++ b/content/browser/host_zoom_map_impl.cc
@@ -90,10 +90,12 @@ void HostZoomMapImpl::SetZoomLevel(const std::string& host, double level) {
     }
   }
 
-  NotificationService::current()->Notify(
-      NOTIFICATION_ZOOM_LEVEL_CHANGED,
-      Source<HostZoomMap>(this),
-      Details<const std::string>(&host));
+  for (std::vector<ZoomLevelChangedCallback>::iterator i =

[jam, 2013/01/30 17:50:44]

nit: here and below, using 

for (size_t i = 0; i < vector_class_.size(); ++i)

is much more readable

[Paweł Hajdan Jr., 2013/01/31 16:02:15]

Done. For deletion I'm still using iterators - I can convert to using indexes,
I'd use an explicit temporary std::vector then.

[jam, 2013/01/31 17:59:15]

not sure why you'd use a temporary std::vector?  a callback should only be in
there once. so

for (size_t i = 0; i < vector_class_.size(); ++i) {
  if (zoom_level_changed_callbacks_[i] == callback) {
    zoom_level_changed_callbacks_.erase(zoom_level_changed_callbacks_.begin() +
i);
    return;
  }
}

should be enough

+           zoom_level_changed_callbacks_.begin();
+       i != zoom_level_changed_callbacks_.end();
+       ++i) {
+    (*i).Run(host);
+  }
 }
 
 double HostZoomMapImpl::GetDefaultZoomLevel() const {
@@ -104,6 +106,23 @@ void HostZoomMapImpl::SetDefaultZoomLevel(double level) {
   default_zoom_level_ = level;
 }
 
+void HostZoomMapImpl::AddZoomLevelChangedCallback(
+    ZoomLevelChangedCallback callback) {
+  zoom_level_changed_callbacks_.push_back(callback);
+}
+
+void HostZoomMapImpl::RemoveZoomLevelChangedCallback(
+    ZoomLevelChangedCallback callback) {
+  for (std::vector<ZoomLevelChangedCallback>::iterator i =
+           zoom_level_changed_callbacks_.begin();
+       i != zoom_level_changed_callbacks_.end();
+       ++i) {
+    if ((*i).Equals(callback)) {
+      i = zoom_level_changed_callbacks_.erase(i);
+    }
+  }
+}
+
 double HostZoomMapImpl::GetTemporaryZoomLevel(int render_process_id,
                                               int render_view_id) const {
   base::AutoLock auto_lock(lock_);
@@ -145,11 +164,12 @@ void HostZoomMapImpl::SetTemporaryZoomLevel(int render_process_id,
     }
   }
 
-  std::string host;
-  NotificationService::current()->Notify(
-      NOTIFICATION_ZOOM_LEVEL_CHANGED,
-      Source<HostZoomMap>(this),
-      Details<const std::string>(&host));
+  for (std::vector<ZoomLevelChangedCallback>::iterator i =
+           zoom_level_changed_callbacks_.begin();
+       i != zoom_level_changed_callbacks_.end();
+       ++i) {
+    (*i).Run(std::string());
+  }
 }
 
 void HostZoomMapImpl::Observe(int type,