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..aaa3ede356759fe1e04fd2403a638a730948ded7 100644
--- a/chrome/browser/ui/browser_dialogs.h
+++ b/chrome/browser/ui/browser_dialogs.h
@@ -10,9 +10,10 @@
 #include <vector>
 
 #include "base/callback.h"
+#include "base/optional.h"
+#include "base/strings/string16.h"
 #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"
 
@@ -159,13 +160,13 @@ payments::PaymentRequestDialog* CreatePaymentRequestDialog(
     payments::PaymentRequest* request);
 
 // Shows the dialog to choose a share target app. |targets| is a list of app
-// titles that will be shown in a list. Calls |callback| with SHARE if an app
-// was chosen, or CANCEL if the dialog was cancelled.
-// TODO(mgiuca): Callback should provide info about the picked app.
+// title and manifest URL pairs that will be shown in a list. If the user picks
+// a target, this calls |callback| with the manifest URL of the chosen target,
+// or returns null if the user cancelled the share.

[sky, 2017/02/03 18:48:42]

By 'returns null' I think you mean supplies null?

[constantina, 2017/02/06 03:02:35]

Done.

 void ShowWebShareTargetPickerDialog(
     gfx::NativeWindow parent_window,
-    const std::vector<base::string16>& targets,
-    const base::Callback<void(SharePickerResult)>& callback);
+    const std::vector<std::pair<base::string16, GURL>>& targets,
+    const base::Callback<void(base::Optional<std::string>)>& callback);
 
 #if defined(OS_MACOSX)