Correct the usage of finalize in TracingControllerAndroid class.

TracingControllerAndroid should destroy its native instance when it
is done instead of relying on finalize() to destroy it, as vm does
not guaranteed finalize() will be called.
(source: http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#finalize%28%29)

Implement destroy() to immediately destroy native instance.

BUG=None.

Review URL: https://codereview.chromium.org/386983002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283177 0039d316-1c4b-4281-b951-d872f2087c98

AUTHORS

@@ -272,6 +272,7 @@ Mirela Budaes <mbudaes@adobe.com>
 Mitchell Rosen <mitchellwrosen@chromium.org>
 Mohamed I. Hammad <ibraaaa@gmail.com>
 Mohamed Mansour <m0.interactive@gmail.com>
+Mohammed Wajahat Ali Siddiqui <wajahat.s@samsung.com>
 Mrunal Kapade <mrunal.kapade@intel.com>
 Myles C. Maxfield <mymax@amazon.com>
 Naiem Shaik <naiem.shaik@gmail.com>

content/public/android/java/src/org/chromium/content/app/ContentApplication.java

@@ -56,6 +56,7 @@ public boolean queueIdle() {
     public void onTerminate() {
         try {
             getTracingController().unregisterReceiver(this);
+            getTracingController().destroy();
         } catch (SecurityException e) {
             // Happens if the process is isolated. Ignore.
         }

content/public/android/java/src/org/chromium/content/browser/TracingControllerAndroid.java

@@ -242,6 +242,15 @@ public void getCategoryGroups() {
 
     @Override
     protected void finalize() {
+        // Ensure that destroy() was called.
+        assert mNativeTracingControllerAndroid == 0;
+    }
+
+    /**
+     * Clean up the C++ side of this class.
+     * After the call, this class instance shouldn't be used.
+     */
+    public void destroy() {
         if (mNativeTracingControllerAndroid != 0) {
             nativeDestroy(mNativeTracingControllerAndroid);
             mNativeTracingControllerAndroid = 0;

content/public/android/javatests/src/org/chromium/content/browser/TracingControllerAndroidTest.java

@@ -61,5 +61,6 @@ public void run() {
         // It says it stopped, so it should have written the output file.
         assertTrue(file.exists());
         assertTrue(file.delete());
+        tracingController.destroy();
     }
 }