Add stubs and glue for routing a request for an image from the clipboard.

ui/base/clipboard/clipboard_win.cc

Index: ui/base/clipboard/clipboard_win.cc
diff --git a/ui/base/clipboard/clipboard_win.cc b/ui/base/clipboard/clipboard_win.cc
index 88a1ff58e6bf350c4d6f38ad63d01406b5612a0a..603779b745400d4cc85da5afc24d9e0c27555942 100644
--- a/ui/base/clipboard/clipboard_win.cc
+++ b/ui/base/clipboard/clipboard_win.cc
@@ -404,6 +404,14 @@ void Clipboard::ReadHTML(Clipboard::Buffer buffer, string16* markup,
     markup->assign(UTF8ToWide(markup_utf8));
 }
 
+void Clipboard::ReadImage(Buffer buffer, std::string* data) const {
+  DCHECK_EQ(buffer, BUFFER_STANDARD);
+  if (!data) {
+    NOTREACHED();
+    return;
+  }
+}
+
 void Clipboard::ReadBookmark(string16* title, std::string* url) const {
   if (title)
     title->clear();