Picker takes a vector of pairs, and passes back the user chosen target.

chrome/browser/ui/browser_dialogs.h

Index: chrome/browser/ui/browser_dialogs.h
diff --git a/chrome/browser/ui/browser_dialogs.h b/chrome/browser/ui/browser_dialogs.h
index 2cdf3e1ee738966c8ad0ab7da083a080a545c388..0c466f3802ac9b5dc20561c7d26b3741400d9951 100644
--- a/chrome/browser/ui/browser_dialogs.h
+++ b/chrome/browser/ui/browser_dialogs.h
@@ -10,9 +10,9 @@
 #include <vector>
 
 #include "base/callback.h"
+#include "base/optional.h"

[Matt Giuca, 2017/01/31 07:28:02]

Need base/strings/string16 as well.

[constantina, 2017/01/31 23:29:42]

Done.

 #include "build/build_config.h"
 #include "chrome/browser/ui/bookmarks/bookmark_editor.h"
-#include "chrome/browser/webshare/share_service_impl.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/native_widget_types.h"
 
@@ -165,7 +165,7 @@ payments::PaymentRequestDialog* CreatePaymentRequestDialog(
 void ShowWebShareTargetPickerDialog(
     gfx::NativeWindow parent_window,
     const std::vector<base::string16>& targets,
-    const base::Callback<void(SharePickerResult)>& callback);
+    const base::Callback<void(base::Optional<base::string16>)>& callback);
 
 #if defined(OS_MACOSX)