Improve process launch handle sharing API.

components/browser_watcher/watcher_client_win.cc

Index: components/browser_watcher/watcher_client_win.cc
diff --git a/components/browser_watcher/watcher_client_win.cc b/components/browser_watcher/watcher_client_win.cc
index d411a2cf6538f8047677b6b5bfee69cc7be77e7b..f062ff5753136c7fa7a38a9b9a98d5de84fdbd54 100644
--- a/components/browser_watcher/watcher_client_win.cc
+++ b/components/browser_watcher/watcher_client_win.cc
@@ -25,10 +25,8 @@ base::Process OpenOwnProcessInheritable() {
 }  // namespace
 
 WatcherClient::WatcherClient(const CommandLineGenerator& command_line_generator)
-    : use_legacy_launch_(base::win::GetVersion() < base::win::VERSION_VISTA),
-      command_line_generator_(command_line_generator),
-      process_(base::kNullProcessHandle) {
-}
+    : command_line_generator_(command_line_generator),
+      process_(base::kNullProcessHandle) {}
 
 WatcherClient::~WatcherClient() {
 }
@@ -41,20 +39,14 @@ void WatcherClient::LaunchWatcher() {
   DCHECK(self.IsValid());
   base::CommandLine cmd_line(command_line_generator_.Run(self.Handle()));
 
-  base::HandlesToInheritVector to_inherit;
   base::LaunchOptions options;
   options.start_hidden = true;
-  if (use_legacy_launch_) {
-    // Launch the child process inheriting all handles on XP.
-    options.inherit_handles = true;
-  } else {
-    // Launch the child process inheriting only |self| on
-    // Vista and better.
-    to_inherit.push_back(self.Handle());
-    to_inherit.insert(to_inherit.end(), inherited_handles_.begin(),
-                      inherited_handles_.end());
-    options.handles_to_inherit = &to_inherit;
-  }
+
+  // Launch the child process inheriting only |self|.
+  options.handles_to_inherit.push_back(self.Handle());
+  options.handles_to_inherit.insert(options.handles_to_inherit.end(),
+                                    inherited_handles_.begin(),
+                                    inherited_handles_.end());
 
   process_ = base::LaunchProcess(cmd_line, options);
   if (!process_.IsValid())