[Android] Remove assert as it uses a non-API backwards compatible function.

BUG=

Review URL: https://codereview.chromium.org/130893004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244036 0039d316-1c4b-4281-b951-d872f2087c98

content/shell/android/java/src/org/chromium/content_shell/Shell.java

@@ -104,8 +104,6 @@ public class Shell extends LinearLayout {
     private void onNativeDestroyed() {
         mWindow = null;
         mNativeShell = 0;
-        assert !mContentView.isAttachedToWindow()
-                : "Attempting to destroy the content view while attached to the view hierarchy.";
         mContentView.destroy();
     }