bindings: Stop using the given creationContext in public APIs.

Source/web/WebBlob.cpp

Index: Source/web/WebBlob.cpp
diff --git a/Source/web/WebBlob.cpp b/Source/web/WebBlob.cpp
index 1cb2e0864439e99661e319cc6ad5a12a49366c41..23727d425acbcbaf411e484e9acfefadc7d5231b 100644
--- a/Source/web/WebBlob.cpp
+++ b/Source/web/WebBlob.cpp
@@ -79,11 +79,13 @@ WebString WebBlob::uuid()
     return m_private->uuid();
 }
 
-v8::Local<v8::Value> WebBlob::toV8Value(v8::Local<v8::Object> creationContext, v8::Isolate* isolate)
+v8::Local<v8::Value> WebBlob::toV8Value(v8::Local<v8::Object> /* creationContext */, v8::Isolate* isolate)
 {
+    // We no longer use |creationContext| because it's often misused and points
+    // to a context faked by user script.
     if (!m_private.get())
         return v8::Local<v8::Value>();
-    return toV8(m_private.get(), creationContext, isolate);
+    return toV8(m_private.get(), isolate->GetCurrentContext()->Global(), isolate);
 }
 
 WebBlob::WebBlob(Blob* blob)