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..0bb8a126a7ec6e7addc8be7b6aa18467a1819e58 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 +4686,22 @@ Vector<IconURL> Document::iconURLs(int iconTypesMask)
     return iconURLs;
 }
 
+HTMLLinkElement* Document::linkManifest() const
+{
+    HTMLHeadElement* head = this->head();
+    if (!head)
+        return 0;
+
+    // The first link element with a manifest rel must be used. Others are ignored.
+    for (HTMLLinkElement* linkElement = Traversal<HTMLLinkElement>::firstChild(*head); linkElement; linkElement = Traversal<HTMLLinkElement>::nextSibling(*linkElement)) {
+        if (!linkElement->relAttribute().isManifest())
+            continue;
+        return linkElement;
+    }
+
+    return 0;
+}
+
 void Document::setUseSecureKeyboardEntryWhenActive(bool usesSecureKeyboard)
 {
     if (m_useSecureKeyboardEntryWhenActive == usesSecureKeyboard)