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

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

Index: device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothAdapter.java
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 0774ea2401b20049095213c710fc17c5970db0a5..51cb5c5c7cbc8390c940946c59631466271b854d 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
@@ -200,6 +200,9 @@ final class ChromeBluetoothAdapter {
         } catch (IllegalArgumentException e) {
             Log.e(TAG, "Cannot start scan: " + e);
             return false;
+        } catch (IllegalStateException e) {

[scheib, 2016/01/21 05:33:51]

Add a test:
- In Fakes.java have FakeBluetoothLeScanner's startScan() check a member
variable that indicates if an exception should be thrown. 
- Set that member variable from some new @CalledByNative method you add to
FakeBluetoothAdapter. 
- Call that method from the test fixture BluetoothTestAndroid, where you also
add a method so that tests can set this behavior.
- Different than existing patterns: because this is very Android implementation
specific, I think only add the method to BluetoothTestAndroid, not to
BluetoothTestBase.
- Add a test to bluetooth_adapter_unittest.cc in the general proximity of
'TEST_F(BluetoothTest, DiscoverySession)'. Comment is clearly as an Android
specific test. 

+            Log.e(TAG, "Adapter is off. Cannot start scan: " + e);
+            return false;
         }
         return true;
     }
@@ -218,6 +221,10 @@ final class ChromeBluetoothAdapter {
             Log.e(TAG, "Cannot stop scan: " + e);
             mScanCallback = null;
             return false;
+        } catch (IllegalStateException e) {
+            Log.e(TAG, "Adapter is off. Cannot stop scan: " + e);
+            mScanCallback = null;
+            return false;
         }
         mScanCallback = null;
         return true;