Correct data size argument type in resource loading path to unsigned

Source/core/fetch/ResourceLoader.cpp

Index: Source/core/fetch/ResourceLoader.cpp
diff --git a/Source/core/fetch/ResourceLoader.cpp b/Source/core/fetch/ResourceLoader.cpp
index 512b3b94d3abde41fda463484c88f3cc989e9958..562109cad2535cac081c318834b2fdad4c6ff403 100644
--- a/Source/core/fetch/ResourceLoader.cpp
+++ b/Source/core/fetch/ResourceLoader.cpp
@@ -437,6 +437,7 @@ void ResourceLoader::didReceiveData(blink::WebURLLoader*, const char* data, int
     m_host->didReceiveData(m_resource, data, length, encodedDataLength);
     if (m_state == Terminated)
         return;
+    ASSERT(length >= 0);

[kouhei (in TOK), 2014/09/30 07:23:03]

is ASSERT safe enough? should we do RELEASE_ASSERT?

[tyoshino (SeeGerritForStatus), 2014/09/30 08:14:28]

Agreed. When negative value is passed to appendData(), underflowed huge value
will be used for appending data to SharedBuffer. We should avoid it even in
release build.

     m_resource->appendData(data, length);
 }