[AiS] Fix ownership issue for image service observers

chrome/browser/bitmap_fetcher/bitmap_fetcher_service_unittest.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/bitmap_fetcher/bitmap_fetcher_service.h"
 
 #include "chrome/browser/bitmap_fetcher/bitmap_fetcher.h"
 #include "chrome/test/base/testing_profile.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
+class TestNotificationInterface {
+ public:
+  virtual ~TestNotificationInterface() {}
+  virtual void OnImageChanged() = 0;
+  virtual void OnRequestFinished() = 0;
+};
+
 class TestObserver : public BitmapFetcherService::Observer {
  public:
-  explicit TestObserver(BitmapFetcherService::Observer* target)
-      : target_(target) {}
-  virtual ~TestObserver() {}
+  explicit TestObserver(TestNotificationInterface* target) : target_(target) {}
+  virtual ~TestObserver() { target_->OnRequestFinished(); }
 
   virtual void OnImageChanged(BitmapFetcherService::RequestId request_id,
                               const SkBitmap& answers_image) OVERRIDE {
-    target_->OnImageChanged(request_id, answers_image);
+    target_->OnImageChanged();
   }
 
-  BitmapFetcherService::Observer* target_;
+  TestNotificationInterface* target_;
 };
 
 class TestService : public BitmapFetcherService {
  public:
   explicit TestService(content::BrowserContext* context)
       : BitmapFetcherService(context) {}
   virtual ~TestService() {}
 
   // Create a fetcher, but don't start downloading. That allows side-stepping
   // the decode step, which requires a utility process.
   virtual chrome::BitmapFetcher* CreateFetcher(const GURL& url) OVERRIDE {
     return new chrome::BitmapFetcher(url, this);
   }
 };
 
 }  // namespace
 
 class BitmapFetcherServiceTest : public testing::Test,
-                                 public BitmapFetcherService::Observer {
+                                 public TestNotificationInterface {
  public:
   virtual void SetUp() OVERRIDE {
     service_.reset(new TestService(&profile_));
     requestsFinished_ = 0;
     imagesChanged_ = 0;
     url1_ = GURL("http://example.org/sample-image-1.png");
     url2_ = GURL("http://example.org/sample-image-2.png");
   }
 
   const ScopedVector<BitmapFetcherRequest>& requests() {
     return service_->requests_;
   }
   const ScopedVector<chrome::BitmapFetcher>& active_fetchers() {
     return service_->active_fetchers_;
   }
   size_t cache_size() { return service_->cache_.size(); }
 
-  virtual void OnImageChanged(BitmapFetcherService::RequestId request_id,
-                              const SkBitmap& answers_image) OVERRIDE {
-    if (answers_image.empty())
-      requestsFinished_++;
-    else
-      imagesChanged_++;
-  }
+  virtual void OnImageChanged() OVERRIDE { imagesChanged_++; }
+
+  virtual void OnRequestFinished() OVERRIDE { requestsFinished_++; }
 
   // Simulate finishing a URL fetch and decode for the given fetcher.
   void CompleteFetch(const GURL& url) {
     const chrome::BitmapFetcher* fetcher = service_->FindFetcherForUrl(url);
     ASSERT_TRUE(NULL != fetcher);
 
     // Create a non-empty bitmap.
     SkBitmap image;
     image.setConfig(SkBitmap::kARGB_8888_Config, 2, 2);
     image.allocPixels();
@@ skipping 73 matching lines @@
   service_->RequestImage(url1_, new TestObserver(this));
   service_->RequestImage(url2_, new TestObserver(this));
   EXPECT_EQ(0U, cache_size());
 
   CompleteFetch(url1_);
   EXPECT_EQ(1U, cache_size());
 
   FailFetch(url2_);
   EXPECT_EQ(1U, cache_size());
 }