[AiS] Fix ownership issue for image service observers

chrome/browser/android/omnibox/answers_image_bridge.cc

Index: chrome/browser/android/omnibox/answers_image_bridge.cc
diff --git a/chrome/browser/android/omnibox/answers_image_bridge.cc b/chrome/browser/android/omnibox/answers_image_bridge.cc
index 5ed9028137943592b43e1ab9e17467447c736f9d..6d19d7c7955c3af7e34f8d423774543db8e24789 100644
--- a/chrome/browser/android/omnibox/answers_image_bridge.cc
+++ b/chrome/browser/android/omnibox/answers_image_bridge.cc
@@ -36,11 +36,7 @@ class AnswersImageObserverAndroid : public BitmapFetcherService::Observer {
   // AnswersImageObserver:
   virtual void OnImageChanged(BitmapFetcherService::RequestId request_id,
                               const SkBitmap& answers_image) OVERRIDE {
-    // An empty image signals a completed request.
-    if (answers_image.empty()) {
-      delete this;
-      return;
-    }
+    DCHECK(!answers_image.empty());
 
     JNIEnv* env = base::android::AttachCurrentThread();
     ScopedJavaLocalRef<jobject> java_bitmap =