Give SxS distribution its own registration GUIDs.

chrome/installer/util/google_chrome_sxs_distribution.cc

Index: chrome/installer/util/google_chrome_sxs_distribution.cc
diff --git a/chrome/installer/util/google_chrome_sxs_distribution.cc b/chrome/installer/util/google_chrome_sxs_distribution.cc
index 1e623d995e45a689b1e0562fc96cdccab5614868..a3b669e9666e457d94b136ab6162d9ca52e34af9 100644
--- a/chrome/installer/util/google_chrome_sxs_distribution.cc
+++ b/chrome/installer/util/google_chrome_sxs_distribution.cc
@@ -17,6 +17,8 @@ const wchar_t kChromeSxSGuid[] = L"{4ea16ac7-fd5a-47c3-875b-dbf4a2008c20}";
 const wchar_t kChannelName[] = L"canary";
 const wchar_t kBrowserAppId[] = L"ChromeCanary";
 const int kSxSIconIndex = 4;
+const wchar_t kCommandExecuteImplUuid[] =
+  L"{1BEAC3E3-B852-44F4-B468-8906C062422E}";
 
 // The Chrome App Launcher Canary icon is index 6; see chrome_exe.rc.
 const int kSxSAppLauncherIconIndex = 6;
@@ -24,7 +26,8 @@ const int kSxSAppLauncherIconIndex = 6;
 }  // namespace
 
 GoogleChromeSxSDistribution::GoogleChromeSxSDistribution()
-    : GoogleChromeDistribution() {
+    : GoogleChromeDistribution(),
+      enable_set_as_default_(false) {
   GoogleChromeDistribution::set_product_guid(kChromeSxSGuid);
 }
 
@@ -64,7 +67,11 @@ string16 GoogleChromeSxSDistribution::GetUninstallRegPath() {
 }
 
 bool GoogleChromeSxSDistribution::CanSetAsDefault() {
-  return false;
+  return enable_set_as_default_;
+}
+
+void GoogleChromeSxSDistribution::DebugEnableSetAsDefault() {
+  enable_set_as_default_ = true;
 }
 
 int GoogleChromeSxSDistribution::GetIconIndex(ShortcutType shortcut_type) {
@@ -82,7 +89,9 @@ bool GoogleChromeSxSDistribution::GetChromeChannel(string16* channel) {
 
 bool GoogleChromeSxSDistribution::GetCommandExecuteImplClsid(
     string16* handler_class_uuid) {
-  return false;
+  if (handler_class_uuid)
+    *handler_class_uuid = kCommandExecuteImplUuid;
+  return true;
 }
 
 bool GoogleChromeSxSDistribution::AppHostIsSupported() {