[NotLanded] Implement the fetching algorithm of the Web Manifest.

Source/web/WebLocalFrameImpl.cpp

Index: Source/web/WebLocalFrameImpl.cpp
diff --git a/Source/web/WebLocalFrameImpl.cpp b/Source/web/WebLocalFrameImpl.cpp
index 4ed3d84b79ed8cf92ccbfbf500873526525e86f2..620bad1325dac169ec4caf0503bf26bb9e9615f2 100644
--- a/Source/web/WebLocalFrameImpl.cpp
+++ b/Source/web/WebLocalFrameImpl.cpp
@@ -117,6 +117,7 @@
 #include "core/loader/FrameLoadRequest.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/HistoryItem.h"
+#include "core/loader/ManifestLoader.h"
 #include "core/loader/SubstituteData.h"
 #include "core/page/Chrome.h"
 #include "core/page/EventHandler.h"
@@ -155,6 +156,7 @@
 #include "public/platform/WebFloatPoint.h"
 #include "public/platform/WebFloatRect.h"
 #include "public/platform/WebLayer.h"
+#include "public/platform/WebManifest.h"
 #include "public/platform/WebPoint.h"
 #include "public/platform/WebRect.h"
 #include "public/platform/WebSize.h"
@@ -1505,6 +1507,12 @@ WebString WebLocalFrameImpl::layerTreeAsText(bool showDebugInfo) const
     return WebString(frame()->layerTreeAsText(showDebugInfo ? LayerTreeIncludesDebugInfo : LayerTreeNormal));
 }
 
+void WebLocalFrameImpl::requestManifest()
+{
+    ASSERT(m_frame);
+    ManifestLoader::loadManifest(m_frame);
+}
+
 // WebLocalFrameImpl public ---------------------------------------------------------
 
 WebLocalFrame* WebLocalFrame::create(WebFrameClient* client)