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

Source/core/dom/Document.h

Index: Source/core/dom/Document.h
diff --git a/Source/core/dom/Document.h b/Source/core/dom/Document.h
index 5131c76b9f30de590195ffc234dbb9ca5d7b3d8d..1058fc7e1284087732304c18275a88a1b2105b1b 100644
--- a/Source/core/dom/Document.h
+++ b/Source/core/dom/Document.h
@@ -312,7 +312,8 @@ public:
         return m_documentElement.get();
     }
 
-    bool hasManifest() const;
+    // Returns whether the Document has an AppCache manifest.
+    bool hasAppCacheManifest() const;
 
     Location* location() const;
 
@@ -853,6 +854,9 @@ public:
 
     Vector<IconURL> iconURLs(int iconTypesMask);
 
+    // Returns the web app manifest URL declared in a <link>.
+    KURL manifestURL();
+
     void setUseSecureKeyboardEntryWhenActive(bool);
     bool useSecureKeyboardEntryWhenActive() const;