Implement the logic to find the correct <link> for Manifest in Document.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 0b4277c3be96e0c2a25dc71792fb3cf47fdc8481..06b2158baf114e185d062fc566feb7272b90504c 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -718,7 +718,7 @@ DOMImplementation& Document::implementation()
     return *m_implementation;
 }
 
-bool Document::hasManifest() const
+bool Document::hasAppCacheManifest() const
 {
     return isHTMLHtmlElement(documentElement()) && documentElement()->hasAttribute(manifestAttr);
 }
@@ -2462,7 +2462,7 @@ void Document::setBody(PassRefPtr<HTMLElement> prpNewBody, ExceptionState& excep
         documentElement()->appendChild(newBody.release(), exceptionState);
 }
 
-HTMLHeadElement* Document::head()
+HTMLHeadElement* Document::head() const
 {
     Node* de = documentElement();
     if (!de)
@@ -4686,6 +4686,18 @@ Vector<IconURL> Document::iconURLs(int iconTypesMask)
     return iconURLs;
 }
 
+HTMLLinkElement* Document::linkManifest() const
+{
+    // The first link element with a manifest rel must be used. Others are ignored.

[Inactive, 2014/05/08 20:13:29]

May be a bit simpler to return early if head() is null:
HTMLHeadElement* head = this->head();
if (!head)
  return 0;
for (HTMLLinkElement* link = Traversal<HTMLLinkElement>::firstChild(*head);
link; link = Traversal<HTMLLinkElement>::nextSibling(*link)) {
  ...
}

[Inactive, 2014/05/10 00:40:20]

Did you disagree with this proposal? It avoided calling head() twice (it is not
inlined) and also avoided 2 null checks if head() returns null.

[mlamouri (slow - plz ping), 2014/05/10 11:28:45]

Eh, sorry about that. I got focused on the tests and forgot to apply that
change. Done now.

+    for (HTMLLinkElement* linkElement = head() ? Traversal<HTMLLinkElement>::firstChild(*head()) : 0; linkElement; linkElement = Traversal<HTMLLinkElement>::nextSibling(*linkElement)) {
+        if (!linkElement->relAttribute().isManifest())
+            continue;
+        return linkElement;
+    }
+
+    return 0;
+}
+
 void Document::setUseSecureKeyboardEntryWhenActive(bool usesSecureKeyboard)
 {
     if (m_useSecureKeyboardEntryWhenActive == usesSecureKeyboard)