Change WebURLLoaderMockFactory for future FOUC tests in blink.

content/test/weburl_loader_mock_factory.cc

Index: content/test/weburl_loader_mock_factory.cc
diff --git a/content/test/weburl_loader_mock_factory.cc b/content/test/weburl_loader_mock_factory.cc
index 64bdea1b8824afe31a2e7a9dd135247dd2b66ade..1651800902696f39314a2dbd40b1782dc5a445a7 100644
--- a/content/test/weburl_loader_mock_factory.cc
+++ b/content/test/weburl_loader_mock_factory.cc
@@ -108,9 +108,7 @@ bool WebURLLoaderMockFactory::IsMockedURL(const blink::WebURL& url) {
 }
 
 void WebURLLoaderMockFactory::CancelLoad(WebURLLoaderMock* loader) {
-  LoaderToRequestMap::iterator iter = pending_loaders_.find(loader);
-  DCHECK(iter != pending_loaders_.end());
-  pending_loaders_.erase(iter);
+  pending_loaders_.erase(loader);
 }
 
 WebURLLoader* WebURLLoaderMockFactory::CreateURLLoader(
@@ -166,6 +164,11 @@ bool WebURLLoaderMockFactory::IsPending(WebURLLoaderMock* loader) {
 // static
 bool WebURLLoaderMockFactory::ReadFile(const base::FilePath& file_path,
                                        WebData* data) {
+  // If the path is empty then we return an empty file so tests can simulate
+  // requests without needing to actually load files.
+  if (file_path.empty())
+    return true;
+
   int64 file_size = 0;
   if (!base::GetFileSize(file_path, &file_size))
     return false;