Fix error prone SynchronizeOnNonFinalField warnings.

chrome/test/android/javatests/src/org/chromium/chrome/test/TestContentProvider.java:112: warning: [SynchronizeOnNonFinalField] Synchronizing on non-final fields is not safe: if the field is ever updated, different threads may end up locking on different objects.
        synchronized (mLock) {

BUG=

Change-Id: Ic11db41809d951fbebfbafd76757833a4f297ebe
Reviewed-on: https://chromium-review.googlesource.com/827535Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524243}

chrome/android/javatests/src/org/chromium/chrome/browser/ShareIntentTest.java

@@ -54,7 +54,7 @@ public class ShareIntentTest {
      * activity and redirects the calls to the methods to the actual activity.
      */
     private static class MockChromeActivity extends ChromeTabbedActivity {
-        private Object mLock = new Object();
+        private final Object mLock = new Object();
         private boolean mCheckCompleted = false;
         private ChromeActivity mActivity = null;
 

chrome/test/android/javatests/src/org/chromium/chrome/test/TestContentProvider.java

@@ -65,7 +65,7 @@ public class TestContentProvider extends ContentProvider {
     private String mDataFilePath;
 
     // Content providers can be accessed from multiple threads.
-    private Object mLock = new Object();
+    private final Object mLock = new Object();
 
     public static String createContentUrl(String target) {
         return CONTENT_SCHEME + AUTHORITY + "/" + target;