Have Node::document() return a reference instead of a pointer

Source/core/html/LinkImport.cpp

Index: Source/core/html/LinkImport.cpp
diff --git a/Source/core/html/LinkImport.cpp b/Source/core/html/LinkImport.cpp
index 31703ac85ef4d7c946b742ef183752ac05a5dd72..f26e23d31fcc6852f3bcff040a5642ece4fb04e7 100644
--- a/Source/core/html/LinkImport.cpp
+++ b/Source/core/html/LinkImport.cpp
@@ -67,12 +67,12 @@ void LinkImport::process()
         return;
     if (!m_owner)
         return;
-    if (!m_owner->document()->frame() && !m_owner->document()->import())
+    if (!m_owner->document().frame() && !m_owner->document().import())
         return;
 
-    if (!m_owner->document()->import()) {
-        ASSERT(m_owner->document()->frame()); // The document should be the master.
-        HTMLImportsController::provideTo(m_owner->document());
+    if (!m_owner->document().import()) {
+        ASSERT(m_owner->document().frame()); // The document should be the master.
+        HTMLImportsController::provideTo(&m_owner->document());
     }
 
     LinkRequestBuilder builder(m_owner);
@@ -81,7 +81,7 @@ void LinkImport::process()
         return;
     }
 
-    HTMLImport* parent = m_owner->document()->import();
+    HTMLImport* parent = m_owner->document().import();
     HTMLImportsController* controller = parent->controller();
     m_loader = controller->createLoader(parent, builder.build(true));
     if (!m_loader) {