[Bluetooth] Pairing system dialog: polish title and height.

Display the dialog title in HTML in order to inherit correct styling
(in a manner consistent with dialogs like InternetConfigDialog), and
set height to 375px, the height of its Settings webui dialog analog.

Bug: 856565
Change-Id: I8b353d849804a4c3066f802fae30a60e33efa60b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1570693Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Ryan Hansberry <hansberry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#651856}

chrome/browser/resources/chromeos/bluetooth_pairing_dialog/bluetooth_pairing_dialog.html

@@ -37,7 +37,8 @@
       </style>
 
       <bluetooth-dialog id="deviceDialog" no-cancel on-close="onDialogClose_"
-          pairing-device="[[pairingDevice_]]">
+          pairing-device="[[pairingDevice_]]"
+          dialog-title="$i18n{bluetoothPairDeviceTitle}">
       </bluetooth-dialog>
     </template>
     <script src="bluetooth_pairing_dialog.js"></script>

chrome/browser/ui/webui/chromeos/bluetooth_pairing_dialog.cc

@@ -21,13 +21,14 @@ namespace chromeos {
 
 namespace {
 
-constexpr int kBluetoothPairingDialogHeight = 350;
+constexpr int kBluetoothPairingDialogHeight = 375;
 
 void AddBluetoothStrings(content::WebUIDataSource* html_source) {
   struct {
     const char* name;
     int id;
   } localized_strings[] = {
+      {"bluetoothPairDeviceTitle", IDS_SETTINGS_BLUETOOTH_PAIR_DEVICE_TITLE},
       {"ok", IDS_OK},
       {"cancel", IDS_CANCEL},
       {"close", IDS_CLOSE},
@@ -68,9 +69,8 @@ BluetoothPairingDialog::BluetoothPairingDialog(
     const base::string16& name_for_display,
     bool paired,
     bool connected)
-    : SystemWebDialogDelegate(
-          GURL(chrome::kChromeUIBluetoothPairingURL),
-          l10n_util::GetStringUTF16(IDS_SETTINGS_BLUETOOTH_PAIR_DEVICE_TITLE)),
+    : SystemWebDialogDelegate(GURL(chrome::kChromeUIBluetoothPairingURL),
+                              base::string16() /* title */),
       address_(address) {
   device_data_.SetString("address", address);
   device_data_.SetString("name", name_for_display);