Revert "Create errors (especially cancellation errors) internally to WebCore, rather"

Source/Platform/chromium/public/Platform.h

Index: Source/Platform/chromium/public/Platform.h
diff --git a/Source/Platform/chromium/public/Platform.h b/Source/Platform/chromium/public/Platform.h
index 6a12c0581701dd83acca1359932209f4126e8179..b6f1c9049184baeb5f8666a67230f675ec904e77 100644
--- a/Source/Platform/chromium/public/Platform.h
+++ b/Source/Platform/chromium/public/Platform.h
@@ -84,7 +84,7 @@ struct WebLocalizedString;
 struct WebSize;
 struct WebURLError;
 
-class WEBKIT_EXPORT Platform {
+class Platform {
 public:
     // HTML5 Database ------------------------------------------------------
 
@@ -273,8 +273,6 @@ public:
     // A suggestion to cache this metadata in association with this URL.
     virtual void cacheMetadata(const WebURL&, double responseTime, const char* data, size_t dataSize) { }
 
-    virtual WebURLError cancelledError(const WebURL&) const;
-
 
     // Plugins -------------------------------------------------------------