ARC: Implement SetWifiEnabledState API.

components/arc/net/arc_net_host_impl.cc

Index: components/arc/net/arc_net_host_impl.cc
diff --git a/components/arc/net/arc_net_host_impl.cc b/components/arc/net/arc_net_host_impl.cc
index 7582d0e5e31d9ca9070b8bac68bda2174d00d89c..ab0dd8e071692d849897a57f5e76b7f6d24e6614 100644
--- a/components/arc/net/arc_net_host_impl.cc
+++ b/components/arc/net/arc_net_host_impl.cc
@@ -14,6 +14,7 @@
 #include "base/time/time.h"
 #include "chromeos/network/network_handler.h"
 #include "chromeos/network/network_state_handler.h"
+#include "chromeos/network/network_type_pattern.h"
 #include "chromeos/network/network_util.h"
 #include "chromeos/network/onc/onc_utils.h"
 #include "components/arc/arc_bridge_service.h"
@@ -140,10 +141,19 @@ void ArcNetHostImpl::GetWifiEnabledState(
     const GetWifiEnabledStateCallback& callback) {
   bool is_enabled = GetStateHandler()->IsTechnologyEnabled(
       chromeos::NetworkTypePattern::WiFi());
-
   callback.Run(is_enabled);
 }
 
+void ArcNetHostImpl::SetWifiEnabledState(
+    bool is_enabled,
+    const SetWifiEnabledStateCallback& callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  GetStateHandler()->SetTechnologyEnabled(
+      chromeos::NetworkTypePattern::WiFi(), is_enabled,
+      chromeos::network_handler::ErrorCallback());

[dcheng, 2016/03/15 23:19:43]

Out of curiosity... how are you supposed to know if it succeeded? The lack of
the error callback being called?

[stevenjb, 2016/03/15 23:31:31]

There's an email thread discussing this. Right now you don't know whether or not
it succeeded or failed. The error callback is so that known failures can be
logged, but in theory it could take ~10 seconds before a 'enabled' change
request succeeds or fails, so at the moment the caller needs to observe
technology state changes and decide how to handle that. (The current UI doesn't
do anything special, it just sends the request reflects the current state).

+  callback.Run();
+}
+
 void ArcNetHostImpl::StartScan() {
   GetStateHandler()->RequestScan();
 }