Roll cros_system_api and use constants pulled in.

This CL rolls the DEPS to pull in the latest cros_system_api, which adds
the constant for the SetAdvertisingIntervals method. It also fixes a few
nits from the CL that added the setAdvertisingIntervals code,
https://codereview.chromium.org/2353133005/

R=ortuno@chromium.org
BUG=637231

Review-Url: https://codereview.chromium.org/2390063002
Cr-Commit-Position: refs/heads/master@{#422712}

DEPS

@@ -379,7 +379,7 @@ deps_os = {
 
     # For Linux and Chromium OS.
     'src/third_party/cros_system_api':
-      Var('chromium_git') + '/chromiumos/platform/system_api.git' + '@' + '6d7653e36068a12f538512f80c4ce77ea2492b92',
+      Var('chromium_git') + '/chromiumos/platform/system_api.git' + '@' + '1b7b261e7757d49fd9035c12e17704e6fe956032',
 
     # Note that this is different from Android's freetype repo.
     'src/third_party/freetype2/src':

device/bluetooth/bluetooth_adapter.h

@@ -444,6 +444,10 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothAdapter
 #if defined(OS_CHROMEOS) || defined(OS_LINUX)
   // Sets the interval between two consecutive advertisements. Valid ranges
   // for the interval are from 20ms to 10.24 seconds, with min <= max.
+  // Note: This is a best effort. The actual interval may vary non-trivially
+  // from the requested intervals. On some hardware, there is a minimum
+  // interval of 100ms. The minimum and maximum values are specified by the
+  // Core 4.2 Spec, Vol 2, Part E, Section 7.8.5.
   virtual void SetAdvertisingInterval(
       const base::TimeDelta& min,
       const base::TimeDelta& max,

device/bluetooth/dbus/bluetooth_le_advertising_manager_client.cc

@@ -114,11 +114,9 @@ class BluetoothAdvertisementManagerClientImpl
                               uint16_t max_interval_ms,
                               const base::Closure& callback,
                               const ErrorCallback& error_callback) override {
-    // TODO(rkc): Replace the string "SetAdvertisingInterval" with the correct
-    // constant in service_constants.h once cros_system_api DEPS are rolled.
     dbus::MethodCall method_call(
         bluetooth_advertising_manager::kBluetoothAdvertisingManagerInterface,
-        "SetAdvertisingIntervals");
+        bluetooth_advertising_manager::kSetAdvertisingIntervals);
 
     dbus::MessageWriter writer(&method_call);
     writer.AppendUint16(min_interval_ms);

device/bluetooth/dbus/fake_bluetooth_le_advertising_manager_client.cc

@@ -18,6 +18,8 @@ namespace bluez {
 namespace {
 
 constexpr char kAdvertisingManagerPath[] = "/fake/hci0";
+// According to the Bluetooth spec, these are the min and max values possible
+// for advertising interval. Core 4.2 Spec, Vol 2, Part E, Section 7.8.5.
 constexpr uint16_t kMinIntervalMs = 20;
 constexpr uint16_t kMaxIntervalMs = 10240;