Expose device RSSI and Tx power via the chrome.bluetooth API.

chrome/browser/extensions/api/bluetooth/bluetooth_api_utils.cc

Index: chrome/browser/extensions/api/bluetooth/bluetooth_api_utils.cc
diff --git a/chrome/browser/extensions/api/bluetooth/bluetooth_api_utils.cc b/chrome/browser/extensions/api/bluetooth/bluetooth_api_utils.cc
index bd7bec3e5f5ac6eb83f1079d719e8f44b3020fd8..4d11779c6a0092a7403b9cbc798dcc9e5bc9dafc 100644
--- a/chrome/browser/extensions/api/bluetooth/bluetooth_api_utils.cc
+++ b/chrome/browser/extensions/api/bluetooth/bluetooth_api_utils.cc
@@ -112,6 +112,18 @@ void BluetoothDeviceToApiDevice(const device::BluetoothDevice& device,
   out->paired.reset(new bool(device.IsPaired()));
   out->connected.reset(new bool(device.IsConnected()));
 
+  if (*out->connected) {
+    int rssi = device.GetRSSI();

[keybuk, 2014/04/27 09:08:44]

RSSI can also be provided when not connected - e.g. RSSI of received Inquiry
results and AD

We should provide those too, and they can go in the same property

[Ilya Sherman, 2014/04/29 00:51:17]

I extended the IDL documentation to specify this, and moved the GetRSSI() call
out of the if stmt.  However, I don't plan to implement fetching the RSSI from
received Inquiry results as part of this CL, because I don't know how to read
that data on Mac.  I instead added a NOTIMPLEMENTED() for that case, as a
reminder to come back to this at a later time.  Does that sound reasonable?

+    if (rssi != BluetoothDevice::kUnknownPower)
+      out->rssi.reset(new int(rssi));
+    int current_transmit_power = device.GetCurrentHostTransmitPower();
+    if (current_transmit_power != BluetoothDevice::kUnknownPower)
+      out->current_host_transmit_power.reset(new int(current_transmit_power));
+    int maximum_transmit_power = device.GetMaximumHostTransmitPower();
+    if (maximum_transmit_power != BluetoothDevice::kUnknownPower)
+      out->maximum_host_transmit_power.reset(new int(maximum_transmit_power));

[keybuk, 2014/04/27 09:08:44]

These on the other hand only make sense when connected

(Inquiry / Advertising TX Power can go in an Adapter property)

[Ilya Sherman, 2014/04/29 00:51:17]

Ack.

+  }
+
   std::vector<std::string>* string_uuids = new std::vector<std::string>();
   const device::BluetoothDevice::UUIDList& uuids = device.GetUUIDs();
   for (device::BluetoothDevice::UUIDList::const_iterator iter = uuids.begin();