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

Source/core/loader/FormSubmission.cpp

Index: Source/core/loader/FormSubmission.cpp
diff --git a/Source/core/loader/FormSubmission.cpp b/Source/core/loader/FormSubmission.cpp
index 13fb0e9f93e2d3c3bb62b4335e1178bfe7c624e5..9b2b86681aa7d3073e7093b50f5fa836e7e14e73 100644
--- a/Source/core/loader/FormSubmission.cpp
+++ b/Source/core/loader/FormSubmission.cpp
@@ -162,8 +162,8 @@ PassRefPtr<FormSubmission> FormSubmission::create(HTMLFormElement* form, const A
             copiedAttributes.setTarget(attributeValue);
     }
 
-    Document* document = form->document();
-    KURL actionURL = document->completeURL(copiedAttributes.action().isEmpty() ? document->url().string() : copiedAttributes.action());
+    Document& document = form->document();
+    KURL actionURL = document.completeURL(copiedAttributes.action().isEmpty() ? document.url().string() : copiedAttributes.action());
     bool isMailtoForm = actionURL.protocolIs("mailto");
     bool isMultiPartForm = false;
     String encodingType = copiedAttributes.encodingType();
@@ -176,7 +176,7 @@ PassRefPtr<FormSubmission> FormSubmission::create(HTMLFormElement* form, const A
         }
     }
 
-    WTF::TextEncoding dataEncoding = isMailtoForm ? UTF8Encoding() : FormDataBuilder::encodingFromAcceptCharset(copiedAttributes.acceptCharset(), document);
+    WTF::TextEncoding dataEncoding = isMailtoForm ? UTF8Encoding() : FormDataBuilder::encodingFromAcceptCharset(copiedAttributes.acceptCharset(), &document);
     RefPtr<DOMFormData> domFormData = DOMFormData::create(dataEncoding.encodingForFormSubmission());
     Vector<pair<String, String> > formValues;
 
@@ -199,7 +199,7 @@ PassRefPtr<FormSubmission> FormSubmission::create(HTMLFormElement* form, const A
     String boundary;
 
     if (isMultiPartForm) {
-        formData = FormData::createMultiPart(*(static_cast<FormDataList*>(domFormData.get())), domFormData->encoding(), document);
+        formData = FormData::createMultiPart(*(static_cast<FormDataList*>(domFormData.get())), domFormData->encoding(), &document);
         boundary = formData->boundary().data();
     } else {
         formData = FormData::create(*(static_cast<FormDataList*>(domFormData.get())), domFormData->encoding(), attributes.method() == GetMethod ? FormData::FormURLEncoded : FormData::parseEncodingType(encodingType));
@@ -212,8 +212,8 @@ PassRefPtr<FormSubmission> FormSubmission::create(HTMLFormElement* form, const A
 
     formData->setIdentifier(generateFormDataIdentifier());
     formData->setContainsPasswordData(containsPasswordData);
-    String targetOrBaseTarget = copiedAttributes.target().isEmpty() ? document->baseTarget() : copiedAttributes.target();
-    RefPtr<FormState> formState = FormState::create(form, formValues, document, trigger);
+    String targetOrBaseTarget = copiedAttributes.target().isEmpty() ? document.baseTarget() : copiedAttributes.target();
+    RefPtr<FormState> formState = FormState::create(form, formValues, &document, trigger);
     return adoptRef(new FormSubmission(copiedAttributes.method(), actionURL, targetOrBaseTarget, encodingType, formState.release(), formData.release(), boundary, event));
 }