bluetooth: android: Fix a couple of crashes when adapter is turned on/off.

device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java

Index: device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java
diff --git a/device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java b/device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java
index 2ccdaae8d7902b71d5ac91620d3d0380b9cc438a..9287f85865b8c6e16c2d07a4959a7a8fa2568cb1 100644
--- a/device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java
+++ b/device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java
@@ -46,13 +46,15 @@ import java.util.UUID;
 class Wrappers {
     private static final String TAG = "Bluetooth";
 
+    public static final int DEVICE_CLASS_UNSPECIFIED = 0x1F00;
+
     /**
      * Wraps android.bluetooth.BluetoothAdapter.
      */
     static class BluetoothAdapterWrapper {
         private final BluetoothAdapter mAdapter;
         protected final ContextWrapper mContext;
-        protected final BluetoothLeScannerWrapper mScanner;
+        protected BluetoothLeScannerWrapper mScannerWrapper;
 
         /**
          * Creates a BluetoothAdapterWrapper using the default
@@ -94,34 +96,42 @@ class Wrappers {
                 Log.i(TAG, "BluetoothAdapterWrapper.create failed: Default adapter not found.");
                 return null;
             } else {
-                return new BluetoothAdapterWrapper(adapter, new ContextWrapper(context),
-                        new BluetoothLeScannerWrapper(adapter.getBluetoothLeScanner()));
+                return new BluetoothAdapterWrapper(adapter, new ContextWrapper(context));
             }
         }
 
-        public BluetoothAdapterWrapper(BluetoothAdapter adapter, ContextWrapper context,
-                BluetoothLeScannerWrapper scanner) {
+        public BluetoothAdapterWrapper(BluetoothAdapter adapter, ContextWrapper context) {
             mAdapter = adapter;
             mContext = context;
-            mScanner = scanner;
-        }
-
-        public ContextWrapper getContext() {
-            return mContext;
         }
 
-        public BluetoothLeScannerWrapper getBluetoothLeScanner() {
-            return mScanner;
+        public boolean disable() {
+            return mAdapter.disable();
         }
 
-        public boolean isEnabled() {
-            return mAdapter.isEnabled();
+        public boolean enable() {
+            return mAdapter.enable();
         }
 
         public String getAddress() {
             return mAdapter.getAddress();
         }
 
+        public BluetoothLeScannerWrapper getBluetoothLeScanner() {
+            BluetoothLeScanner scanner = mAdapter.getBluetoothLeScanner();
+            if (scanner == null) {
+                return null;
+            }
+            if (mScannerWrapper == null) {
+                mScannerWrapper = new BluetoothLeScannerWrapper(scanner);
+            }
+            return mScannerWrapper;
+        }
+
+        public ContextWrapper getContext() {
+            return mContext;
+        }
+
         public String getName() {
             return mAdapter.getName();
         }
@@ -133,6 +143,10 @@ class Wrappers {
         public boolean isDiscovering() {
             return mAdapter.isDiscovering();
         }
+
+        public boolean isEnabled() {
+            return mAdapter.isEnabled();
+        }
     }
 
     /**
@@ -155,7 +169,7 @@ class Wrappers {
      * Wraps android.bluetooth.BluetoothLeScanner.
      */
     static class BluetoothLeScannerWrapper {
-        private final BluetoothLeScanner mScanner;
+        protected final BluetoothLeScanner mScanner;
         private final HashMap<ScanCallbackWrapper, ForwardScanCallbackToWrapper> mCallbacks;
 
         public BluetoothLeScannerWrapper(BluetoothLeScanner scanner) {
@@ -276,6 +290,11 @@ class Wrappers {
         }
 
         public int getBluetoothClass_getDeviceClass() {
+            if (mDevice == null || mDevice.getBluetoothClass() == null) {
+                // BluetoothDevice.getBluetoothClass() returns null if adapter has been powered off.
+                // Return DEVICE_CLASS_UNSPECIFIED in these cases.
+                return DEVICE_CLASS_UNSPECIFIED;
+            }
             return mDevice.getBluetoothClass().getDeviceClass();
         }