Add viewport settings for ImageDocument and MediaDocument

Source/core/html/ImageDocument.cpp

Index: Source/core/html/ImageDocument.cpp
diff --git a/Source/core/html/ImageDocument.cpp b/Source/core/html/ImageDocument.cpp
index eb594be11f70d34d54a0741142c7a7222f1e1ae9..743b3b6943c624666335cd211a89273c1cc10053 100644
--- a/Source/core/html/ImageDocument.cpp
+++ b/Source/core/html/ImageDocument.cpp
@@ -191,7 +191,15 @@ void ImageDocument::createDocumentStructure()
 
     if (frame() && frame()->loader())
         frame()->loader()->dispatchDocumentElementAvailable();
-    
+
+    RefPtr<Element> head = document()->createElement(headTag, false);
+    rootElement->appendChild(head, IGNORE_EXCEPTION);
+
+    RefPtr<Element> meta = document()->createElement(metaTag, false);
+    meta->setAttribute(nameAttr, "viewport");
+    meta->setAttribute(contentAttr, "width=device-width");
+    head->appendChild(meta, IGNORE_EXCEPTION);
+
     RefPtr<Element> body = Document::createElement(bodyTag, false);
     body->setAttribute(styleAttr, "margin: 0px;");