bluetooth: android: register for adapter on/off events followup.

Followup changes requested by tedchoc on https://codereview.chromium.org/1711393002

BUG=543060

Review URL: https://codereview.chromium.org/1745463002

Cr-Commit-Position: refs/heads/master@{#378022}

3 files changed, 15 insertions, 9 deletions

diff --git a/chrome/browser/ui/android/bluetooth_chooser_android.cc b/chrome/browser/ui/android/bluetooth_chooser_android.cc
index d08203f..5631e64 100644
--- a/chrome/browser/ui/android/bluetooth_chooser_android.cc
+++ b/chrome/browser/ui/android/bluetooth_chooser_android.cc
@@ -62,12 +62,12 @@ bool BluetoothChooserAndroid::CanAskForScanningPermission() {
 }
 
 void BluetoothChooserAndroid::SetAdapterPresence(AdapterPresence presence) {
+  JNIEnv* env = AttachCurrentThread();
   if (presence != AdapterPresence::POWERED_ON) {
-    Java_BluetoothChooserDialog_notifyAdapterTurnedOff(AttachCurrentThread(),
-                                                       java_dialog_.obj());
+    Java_BluetoothChooserDialog_notifyAdapterTurnedOff(env, java_dialog_.obj());
   } else {
-    Java_BluetoothChooserDialog_notifyAdapterTurnedOn(AttachCurrentThread(),
-                                                      java_dialog_.obj());
+    Java_BluetoothChooserDialog_notifyAdapterTurnedOn(env, java_dialog_.obj());
+    RestartSearch();
   }
 }
 
@@ -130,11 +130,15 @@ void BluetoothChooserAndroid::OnDialogFinished(
   NOTREACHED();
 }
 
-void BluetoothChooserAndroid::RestartSearch(JNIEnv* env,
-                                            const JavaParamRef<jobject>& obj) {
+void BluetoothChooserAndroid::RestartSearch() {
   event_handler_.Run(Event::RESCAN, "");
 }
 
+void BluetoothChooserAndroid::RestartSearch(JNIEnv*,
+                                            const JavaParamRef<jobject>&) {
+  RestartSearch();
+}
+
 void BluetoothChooserAndroid::ShowBluetoothOverviewLink(
     JNIEnv* env,
     const JavaParamRef<jobject>& obj) {
diff --git a/chrome/browser/ui/android/bluetooth_chooser_android.h b/chrome/browser/ui/android/bluetooth_chooser_android.h
index fc77e63..0af0b1a 100644
--- a/chrome/browser/ui/android/bluetooth_chooser_android.h
+++ b/chrome/browser/ui/android/bluetooth_chooser_android.h
@@ -37,8 +37,9 @@ class BluetoothChooserAndroid : public content::BluetoothChooser {
                         const base::android::JavaParamRef<jstring>& device_id);
 
   // Notify bluetooth stack that the search needs to be re-issued.
-  void RestartSearch(JNIEnv* env,
-                     const base::android::JavaParamRef<jobject>& obj);
+  void RestartSearch();
+  // Calls RestartSearch(). Unused JNI parameters enable calls from Java.
+  void RestartSearch(JNIEnv*, const base::android::JavaParamRef<jobject>&);
 
   void ShowBluetoothOverviewLink(
       JNIEnv* env,
diff --git a/device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothAdapter.java b/device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothAdapter.java
index 54a8eb9..a7751f7 100644
--- a/device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothAdapter.java
+++ b/device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothAdapter.java
@@ -34,7 +34,8 @@ final class ChromeBluetoothAdapter extends BroadcastReceiver {
     private static final String TAG = "Bluetooth";
 
     private long mNativeBluetoothAdapterAndroid;
-    private Wrappers.BluetoothAdapterWrapper mAdapter;
+    // mAdapter is final to ensure registerReceiver is followed by unregisterReceiver.
+    private final Wrappers.BluetoothAdapterWrapper mAdapter;
     private int mNumDiscoverySessions;
     private ScanCallback mScanCallback;