Phase II Step 3: Reload LoFi/placeholder images via new ImageResource

third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp

Index: third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp
diff --git a/third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp b/third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp
index 1d35e159ac55f11d369f885c2958d02f23da2541..359fff5ad0c77bd62f8f215e568f3b418883ec0a 100644
--- a/third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp
+++ b/third_party/WebKit/Source/platform/loader/fetch/ResourceFetcher.cpp
@@ -513,6 +513,11 @@ ResourceFetcher::PrepareRequestResult ResourceFetcher::prepareRequest(
   return Continue;
 }
 
+void ResourceFetcher::addToDocumentResources(Resource* resource) {
+  m_documentResources.set(
+      MemoryCache::removeFragmentIdentifierIfNeeded(resource->url()), resource);
+}
+
 Resource* ResourceFetcher::requestResource(
     FetchRequest& request,
     const ResourceFactory& factory,
@@ -612,8 +617,7 @@ Resource* ResourceFetcher::requestResource(
       identifier, resource, request,
       policy == Use ? ResourceLoadingFromCache : ResourceLoadingFromNetwork,
       isStaticData);
-  m_documentResources.set(
-      MemoryCache::removeFragmentIdentifierIfNeeded(request.url()), resource);
+  addToDocumentResources(resource);
 
   // Returns with an existing resource if the resource does not need to start
   // loading immediately. If revalidation policy was determined as |Revalidate|,
@@ -1332,8 +1336,12 @@ void ResourceFetcher::updateAllImageResourcePriorities() {
 }
 
 void ResourceFetcher::reloadLoFiImages() {
-  for (const auto& documentResource : m_documentResources) {
-    Resource* resource = documentResource.value.get();
+  // We copy entries of |m_documentResources| first because
+  // reloadIfLoFiOrPlaceholderImage() can modify |m_documentResources|.
+  HeapVector<Member<Resource>> documentResources;
+  copyValuesToVector(m_documentResources, documentResources);
+  for (const auto& documentResource : documentResources) {
+    Resource* resource = documentResource.get();
     if (resource)
       resource->reloadIfLoFiOrPlaceholderImage(this, Resource::kReloadAlways);
   }