[AiS] Fix ownership issue for image service observers

chrome/browser/android/omnibox/answers_image_bridge.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/android/omnibox/answers_image_bridge.h"
 
 #include <jni.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
@@ skipping 18 matching lines @@
   explicit AnswersImageObserverAndroid(JNIEnv* env,
                                        jobject java_answers_image_observer) {
     java_answers_image_observer_.Reset(env, java_answers_image_observer);
   }
 
   virtual ~AnswersImageObserverAndroid() {}
 
   // 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 =
         gfx::ConvertToJavaBitmap(&answers_image);
     Java_AnswersImageObserver_onAnswersImageChanged(
         env, java_answers_image_observer_.obj(), java_bitmap.obj());
   }
 
  private:
   base::android::ScopedJavaGlobalRef<jobject> java_answers_image_observer_;
@@ skipping 24 matching lines @@
   std::string url;
   base::android::ConvertJavaStringToUTF8(env, java_url, &url);
   return bitmap_fetcher_service->RequestImage(
       GURL(url), new AnswersImageObserverAndroid(env, java_callback));
 }
 
 // static
 bool RegisterAnswersImageBridge(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }