Create a Tether section in the system tray network list.

chromeos/network/network_state_handler.cc

Index: chromeos/network/network_state_handler.cc
diff --git a/chromeos/network/network_state_handler.cc b/chromeos/network/network_state_handler.cc
index eaed6e9ce3c70e4908cc14f6f4b8b1ca8aae67cc..2c23bd3285d3a1f79b76a13ef67dcb5c3d997805 100644
--- a/chromeos/network/network_state_handler.cc
+++ b/chromeos/network/network_state_handler.cc
@@ -7,6 +7,7 @@
 #include <stddef.h>
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "base/format_macros.h"
 #include "base/guid.h"
 #include "base/json/json_string_value_serializer.h"
@@ -19,6 +20,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
+#include "chromeos/chromeos_switches.h"
 #include "chromeos/network/device_state.h"
 #include "chromeos/network/network_event_log.h"
 #include "chromeos/network/network_state.h"
@@ -133,7 +135,13 @@ NetworkStateHandler::TechnologyState NetworkStateHandler::GetTechnologyState(
     state = TECHNOLOGY_UNINITIALIZED;
   else if (shill_property_handler_->IsTechnologyAvailable(technology))
     state = TECHNOLOGY_AVAILABLE;
-  else
+  else if (technology == kTypeTether &&
+           base::CommandLine::ForCurrentProcess()->HasSwitch(
+               chromeos::switches::kEnableTether)) {
+    // TODO (hansberry): Provide Tether a way to enable and disable the
+    // technology.
+    state = TECHNOLOGY_ENABLED;

[stevenjb, 2017/02/21 22:43:56]

If we but {} around one if clause, we should put it around all of them.

Alternatively we could move this up since it isn't a shill thing, i.e.

if (technology == tether) {
  return (tether enabled) ? ENABLED : UNAVAILABLE;
}

The VLOG below isn't important, but you could add a separate one for your
debugging if you want.

[Ryan Hansberry, 2017/02/21 23:26:37]

Done. Decided to not add a VLOG.

+  } else
     state = TECHNOLOGY_UNAVAILABLE;
   VLOG(2) << "GetTechnologyState: " << type.ToDebugString() << " = " << state;
   return state;
@@ -307,6 +315,20 @@ void NetworkStateHandler::GetNetworkListByType(const NetworkTypePattern& type,
   }
 }
 
+void NetworkStateHandler::GetTetherNetworkList(int limit,
+                                               NetworkStateList* list) {
+  DCHECK(list);
+  list->clear();
+  int count = 0;
+
+  for (auto iter = tether_network_list_.begin();
+       iter != tether_network_list_.end(); ++iter) {
+    list->push_back((*iter)->AsNetworkState());
+    if (limit > 0 && ++count >= limit)
+      return;
+  }
+}
+
 const NetworkState* NetworkStateHandler::GetNetworkStateFromServicePath(
     const std::string& service_path,
     bool configured_only) const {
@@ -343,9 +365,19 @@ const NetworkState* NetworkStateHandler::GetNetworkStateFromGuid(
   return nullptr;
 }
 
-const std::string NetworkStateHandler::CreateTetherNetworkState(
-    const std::string& name) {
-  const std::string& guid = base::GenerateGUID();
+void NetworkStateHandler::AddTetherNetworkState(const std::string& guid,
+                                                const std::string& name) {
+#if DCHECK_IS_ON()

[stevenjb, 2017/02/21 22:43:56]

This #if is only needed if there is logic other than just the DCHECK inside it.

[Ryan Hansberry, 2017/02/21 23:26:37]

Done.

+  DCHECK(!guid.empty());
+#endif
+
+  // If the network already exists, do nothing.
+  for (auto iter = tether_network_list_.begin();
+       iter != tether_network_list_.end(); ++iter) {
+    if (iter->get()->AsNetworkState()->guid() == guid) {

[stevenjb, 2017/02/21 22:43:56]

I would add:
NET_LOG(ERROR) << "Add tether network: " << name << " called with existing guid:
" << guid;

[Ryan Hansberry, 2017/02/21 23:26:37]

Done.

+      return;
+    }
+  }
 
   std::unique_ptr<NetworkState> tether_managed_state =
       base::MakeUnique<NetworkState>(base::GenerateGUID());
@@ -357,8 +389,6 @@ const std::string NetworkStateHandler::CreateTetherNetworkState(
 
   tether_network_list_.push_back(std::move(tether_managed_state));
   NotifyNetworkListChanged();
-
-  return guid;
 }
 
 void NetworkStateHandler::RemoveTetherNetworkState(const std::string& guid) {
@@ -1028,6 +1058,9 @@ std::string NetworkStateHandler::GetTechnologyForType(
   if (type.MatchesType(shill::kTypeCellular))
     return shill::kTypeCellular;
 
+  if (type.MatchesType(kTypeTether))
+    return kTypeTether;
+
   NOTREACHED();
   return std::string();
 }