Make calls to AtomicString(const String&) explicit in loader/ and fetch/

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 40 matching lines @@
 
 TEST(ImageResourceTest, MultipartImage)
 {
     ResourcePtr<ImageResource> cachedImage = new ImageResource(ResourceRequest());
     cachedImage->setLoading(true);
 
     MockImageResourceClient client;
     cachedImage->addClient(&client);
 
     // Send the multipart response. No image or data buffer is created.
-    cachedImage->responseReceived(ResourceResponse(KURL(), "multipart/x-mixed-replace", 0, String(), String()));
+    cachedImage->responseReceived(ResourceResponse(KURL(), "multipart/x-mixed-replace", 0, nullAtom, String()));
     ASSERT_FALSE(cachedImage->resourceBuffer());
     ASSERT_FALSE(cachedImage->hasImage());
     ASSERT_EQ(client.imageChangedCount(), 0);
     ASSERT_FALSE(client.notifyFinishedCalled());
 
     // Send the response for the first real part. No image or data buffer is created.
     const char* svgData = "<svg xmlns='http://www.w3.org/2000/svg' width='1' height='1'><rect width='1' height='1' fill='green'/></svg>";
     unsigned svgDataLength = strlen(svgData);
-    cachedImage->responseReceived(ResourceResponse(KURL(), "image/svg+xml", svgDataLength, String(), String()));
+    cachedImage->responseReceived(ResourceResponse(KURL(), "image/svg+xml", svgDataLength, nullAtom, String()));
     ASSERT_FALSE(cachedImage->resourceBuffer());
     ASSERT_FALSE(cachedImage->hasImage());
     ASSERT_EQ(client.imageChangedCount(), 0);
     ASSERT_FALSE(client.notifyFinishedCalled());
 
     // The first bytes arrive. The data buffer is created, but no image is created.
     cachedImage->appendData(svgData, svgDataLength);
     ASSERT_TRUE(cachedImage->resourceBuffer());
     ASSERT_EQ(cachedImage->resourceBuffer()->size(), svgDataLength);
     ASSERT_FALSE(cachedImage->hasImage());
@@ skipping 44 matching lines @@
 
     // Trigger the cancel timer, ensure the load was cancelled and the resource was evicted from the cache.
     WebCore::testing::runPendingTasks();
     EXPECT_EQ(Resource::LoadError, cachedImage->status());
     EXPECT_EQ(reinterpret_cast<Resource*>(0), memoryCache()->resourceForURL(testURL));
 
     blink::Platform::current()->unitTestSupport()->unregisterMockedURL(testURL);
 }
 
 } // namespace