Detect <link rel='manifest'> and notify embedder.

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 86fedec952c8e36adf6b3012c142075b84d6b05c..da299f9025fdfd62c305895b4ca618f9f7eed05b 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -704,7 +704,7 @@ DOMImplementation& Document::implementation()
     return *m_implementation;
 }
 
-bool Document::hasManifest() const
+bool Document::hasAppCacheManifest() const
 {
     return isHTMLHtmlElement(documentElement()) && documentElement()->hasAttribute(manifestAttr);
 }
@@ -4670,6 +4670,18 @@ Vector<IconURL> Document::iconURLs(int iconTypesMask)
     return iconURLs;
 }
 
+KURL Document::manifestURL()
+{
+    // The first link element with a manifest rel must be used. Others are ignored.
+    for (HTMLLinkElement* linkElement = head() ? Traversal<HTMLLinkElement>::firstChild(*head()) : 0; linkElement; linkElement = Traversal<HTMLLinkElement>::nextSibling(*linkElement)) {
+        if (!linkElement->relAttribute().isManifest())
+            continue;
+        return linkElement->href();
+    }
+
+    return KURL();
+}
+
 void Document::setUseSecureKeyboardEntryWhenActive(bool usesSecureKeyboard)
 {
     if (m_useSecureKeyboardEntryWhenActive == usesSecureKeyboard)