Reland "Ensure |m_image| is (re-)created in ImageResource::didAddClient()"

third_party/WebKit/Source/core/fetch/ImageResourceTest.cpp

 /*
  * Copyright (c) 2013, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 289 matching lines @@
     cachedImage->loader()->didReceiveResponse(nullptr, WrappedResourceResponse(resourceResponse), nullptr);
     cachedImage->loader()->didReceiveData(nullptr, reinterpret_cast<const char*>(jpeg.data()), jpeg.size(), jpeg.size());
     cachedImage->loader()->didFinishLoading(nullptr, 0.0, jpeg.size());
     ASSERT_FALSE(cachedImage->errorOccurred());
     ASSERT_TRUE(cachedImage->hasImage());
     ASSERT_FALSE(cachedImage->getImage()->isNull());
     ASSERT_TRUE(client->notifyFinishedCalled());
     ASSERT_TRUE(cachedImage->getImage()->isBitmapImage());
 }
 
+// Tests for pruning.
+
+TEST(ImageResourceTest, AddClientAfterPrune)
+{
+    KURL url(ParsedURLString, "http://127.0.0.1:8000/foo");
+    ImageResource* imageResource = ImageResource::create(ResourceRequest(url));
+
+    // Adds a ResourceClient but not ImageResourceObserver.
+    Persistent<MockResourceClient> client1 = new MockResourceClient(imageResource);
+
+    Vector<unsigned char> jpeg = jpegImage();
+    ResourceResponse response;
+    response.setURL(url);
+    response.setHTTPStatusCode(200);
+    response.setMimeType("image/jpeg");
+    imageResource->responseReceived(response, nullptr);
+    imageResource->appendData(reinterpret_cast<const char*>(jpeg.data()), jpeg.size());
+    imageResource->finish();
+
+    EXPECT_FALSE(imageResource->errorOccurred());
+    ASSERT_TRUE(imageResource->hasImage());
+    EXPECT_FALSE(imageResource->getImage()->isNull());
+    EXPECT_EQ(1, imageResource->getImage()->width());
+    EXPECT_EQ(1, imageResource->getImage()->height());
+    EXPECT_TRUE(client1->notifyFinishedCalled());
+
+    client1->removeAsClient();
+
+    EXPECT_FALSE(imageResource->hasClientsOrObservers());
+
+    imageResource->prune();
+
+    EXPECT_FALSE(imageResource->hasImage());
+
+    // Re-adds a ResourceClient but not ImageResourceObserver.
+    Persistent<MockResourceClient> client2 = new MockResourceClient(imageResource);
+
+    ASSERT_TRUE(imageResource->hasImage());
+    EXPECT_FALSE(imageResource->getImage()->isNull());
+    EXPECT_EQ(1, imageResource->getImage()->width());
+    EXPECT_EQ(1, imageResource->getImage()->height());
+    EXPECT_TRUE(client2->notifyFinishedCalled());
+}
+
 } // namespace blink