Removal of rel=preload link elements should stop the download.

third_party/WebKit/Source/core/loader/LinkPreloadResourceClients.h

Index: third_party/WebKit/Source/core/loader/LinkPreloadResourceClients.h
diff --git a/third_party/WebKit/Source/core/loader/LinkPreloadResourceClients.h b/third_party/WebKit/Source/core/loader/LinkPreloadResourceClients.h
index f73ac7237fca3469226138fef928e319666ed089..b7fd972d89e37ee23f315903d8d5f5d4fc611692 100644
--- a/third_party/WebKit/Source/core/loader/LinkPreloadResourceClients.h
+++ b/third_party/WebKit/Source/core/loader/LinkPreloadResourceClients.h
@@ -8,6 +8,7 @@
 #include "core/fetch/CSSStyleSheetResource.h"
 #include "core/fetch/FontResource.h"
 #include "core/fetch/ImageResourceClient.h"
+#include "core/fetch/ResourceLoader.h"
 #include "core/fetch/ResourceOwner.h"
 #include "core/fetch/ScriptResource.h"
 #include "core/fetch/StyleSheetResourceClient.h"
@@ -22,6 +23,8 @@ public:
 
     void triggerEvents(const Resource*);
 
+    virtual void cancel() = 0;
+
     DEFINE_INLINE_VIRTUAL_TRACE()
     {
         visitor->trace(m_loader);
@@ -61,6 +64,12 @@ public:
         ResourceOwner<ScriptResource, ScriptResourceClient>::trace(visitor);
     }
 
+    void cancel() override
+    {
+        if (resource() && resource()->loader())
+            resource()->loader()->cancel();

[Nate Chapin, 2016/01/21 19:03:50]

This will cancel the load even if the preload is now being used by a real load.
That seems wrong?

[Yoav Weiss, 2016/01/21 21:51:21]

yeah. changed to clearResource()

+    }
+
 private:
     LinkPreloadScriptResourceClient(LinkLoader* loader, ScriptResource* resource)
         : LinkPreloadResourceClient(loader)
@@ -92,6 +101,12 @@ public:
         ResourceOwner<CSSStyleSheetResource, StyleSheetResourceClient>::trace(visitor);
     }
 
+    void cancel() override
+    {
+        if (resource() && resource()->loader())
+            resource()->loader()->cancel();
+    }
+
 private:
     LinkPreloadStyleResourceClient(LinkLoader* loader, CSSStyleSheetResource* resource)
         : LinkPreloadResourceClient(loader)