Fix registerProtocolHandler implementation on Windows 8 and 10.

chrome/browser/shell_integration_win.cc

Index: chrome/browser/shell_integration_win.cc
diff --git a/chrome/browser/shell_integration_win.cc b/chrome/browser/shell_integration_win.cc
index 9a92a9c438eacc3dd186c19701c4a74d41639d37..0461b684d47c73e802e0605f41a22e5d28a5484f 100644
--- a/chrome/browser/shell_integration_win.cc
+++ b/chrome/browser/shell_integration_win.cc
@@ -43,6 +43,7 @@
 #include "chrome/installer/util/browser_distribution.h"
 #include "chrome/installer/util/create_reg_key_work_item.h"
 #include "chrome/installer/util/install_util.h"
+#include "chrome/installer/util/scoped_user_protocol_entry.h"
 #include "chrome/installer/util/set_reg_value_work_item.h"
 #include "chrome/installer/util/shell_util.h"
 #include "chrome/installer/util/util_constants.h"
@@ -237,7 +238,7 @@ class OpenSystemSettingsHelper {
  public:
   // Begin the monitoring and will call |on_finished_callback| when done.
   // Takes in a null-terminated array of |protocols| whose registry keys must be
-  // watched.
+  // watched. The array must contain at least one element.
   static void Begin(const wchar_t* const protocols[],
                     const base::Closure& on_finished_callback) {
     new OpenSystemSettingsHelper(protocols, on_finished_callback);
@@ -250,7 +251,9 @@ class OpenSystemSettingsHelper {
 
   OpenSystemSettingsHelper(const wchar_t* const protocols[],
                            const base::Closure& on_finished_callback)
-      : on_finished_callback_(on_finished_callback), weak_ptr_factory_(this) {
+      : scoped_user_protocol_entry_(protocols[0]),
+        on_finished_callback_(on_finished_callback),
+        weak_ptr_factory_(this) {
     static const wchar_t kUrlAssociationFormat[] =
         L"SOFTWARE\\Microsoft\\Windows\\Shell\\Associations\\UrlAssociations\\"
         L"%ls\\UserChoice";
@@ -315,6 +318,8 @@ class OpenSystemSettingsHelper {
     }
   }
 
+  ScopedUserProtocolEntry scoped_user_protocol_entry_;

[grt (UTC plus 2), 2016/04/18 19:00:56]

nit: a comment here would be helpful to understand why this is here.

on second thought, does this need to be here in shell_integration? can it be
done inside Show*SystemUI for both the Win8 and Win10+ cases?

[grt (UTC plus 2), 2016/04/19 02:03:46]

as per face-to-face discussion, i understand this is needed here because the
cleanup must happen in the helper's dtor. i think this is okay.

are we now in a world where ShellUtil::ShowMakeChromeDefaultSystemUI and
ShowMakeChromeDefaultProtocolClientSystemUI should never be called directly on
Win10 since we always want the benefits of the helper? can we get rid of all
other callers of these two functions and paint them with colours too painful to
see so that noone ever calls them again (preferring the functions in
shell_integrtion)?

[Patrick Monette, 2016/04/19 14:36:13]

I added a comment. I think shell util is due for a refactoring. I'll do it in
another CL.

+
   // The function to call when the interaction with the system settings is
   // finished.
   base::Closure on_finished_callback_;
@@ -689,6 +694,28 @@ bool SetAsDefaultProtocolClientUsingIntentPicker(const std::string& protocol) {
   return true;
 }
 
+void SetAsDefaultProtocolClientUsingSystemSettings(
+    const std::string& protocol,
+    const base::Closure& on_finished_callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
+
+  base::FilePath chrome_exe;
+  if (!PathService::Get(base::FILE_EXE, &chrome_exe)) {
+    NOTREACHED() << "Error getting app exe path";
+    on_finished_callback.Run();
+    return;
+  }
+
+  // The helper manages its own lifetime.
+  base::string16 wprotocol(base::UTF8ToUTF16(protocol));
+  static const wchar_t* const kProtocols[] = {wprotocol.c_str(), nullptr};
+  OpenSystemSettingsHelper::Begin(kProtocols, on_finished_callback);
+
+  BrowserDistribution* dist = BrowserDistribution::GetDistribution();
+  ShellUtil::ShowMakeChromeDefaultProtocolClientSystemUI(dist, chrome_exe,
+                                                         wprotocol);
+}
+
 }  // namespace win
 
 }  // namespace shell_integration