Enable pairing registry in me2me native messaging host on Windows

remoting/host/setup/me2me_native_messaging_host_main.cc

Index: remoting/host/setup/me2me_native_messaging_host_main.cc
diff --git a/remoting/host/setup/me2me_native_messaging_host_main.cc b/remoting/host/setup/me2me_native_messaging_host_main.cc
index 638b15be44b7756e3c8a12630ca3ca3c98b466d8..27ca189a300a25bb7f4fcb41c16aeee0c70b3f2c 100644
--- a/remoting/host/setup/me2me_native_messaging_host_main.cc
+++ b/remoting/host/setup/me2me_native_messaging_host_main.cc
@@ -14,9 +14,13 @@
 #include "remoting/host/setup/me2me_native_messaging_host.h"
 
 #if defined(OS_WIN)
+#include "base/win/registry.h"
 #include "base/win/windows_version.h"
+#include "remoting/host/pairing_registry_delegate_win.h"
 #endif  // defined(OS_WIN)
 
+using remoting::protocol::PairingRegistry;
+
 namespace {
 
 const char kParentWindowSwitchName[] = "parent-window";
@@ -140,14 +144,61 @@ int Me2MeNativeMessagingHostMain() {
 
   net::URLFetcher::SetIgnoreCertificateRequests(true);
 
-  // Create the pairing registry and native messaging host.
-  scoped_refptr<protocol::PairingRegistry> pairing_registry =
+  // Create the pairing registry.
+  scoped_refptr<PairingRegistry> pairing_registry;
+
+#if defined(OS_WIN)
+  base::win::RegKey root;
+  LONG result = root.Open(HKEY_LOCAL_MACHINE, kPairingRegistryKeyName,
+                          KEY_READ);
+  if (result != ERROR_SUCCESS) {
+    SetLastError(result);
+    PLOG(ERROR) << "Failed to open HKLM\\" << kPairingRegistryKeyName;
+    return kInitializationFailed;
+  }
+
+  base::win::RegKey unprivileged;
+  result = unprivileged.Open(root.Handle(), kUnprivilegedKeyName,
+                             needs_elevation ? KEY_READ : KEY_READ | KEY_WRITE);
+  if (result != ERROR_SUCCESS) {
+    SetLastError(result);
+    PLOG(ERROR) << "Failed to open HKLM\\" << kUnprivilegedKeyName << "\\"
+                << kUnprivilegedKeyName;
+    return kInitializationFailed;
+  }
+
+  // Only try to open the privileged key if the current process is elevated.
+  base::win::RegKey privileged;
+  if (!needs_elevation) {
+    result = privileged.Open(root.Handle(), kPrivilegedKeyName,
+                             KEY_READ | KEY_WRITE);
+    if (result != ERROR_SUCCESS) {
+      SetLastError(result);
+      PLOG(ERROR) << "Failed to open HKLM\\" << kPairingRegistryKeyName << "\\"
+                  << kPrivilegedKeyName;
+      return kInitializationFailed;
+    }
+  }
+
+  // Initialize the pairing registry delegate and set the root keys.
+  scoped_ptr<PairingRegistryDelegateWin> delegate(
+      new PairingRegistryDelegateWin());
+  if (!delegate->SetRootKeys(privileged.Take(), unprivileged.Take()))
+    return kInitializationFailed;
+
+  pairing_registry = new PairingRegistry(
+      io_thread.message_loop_proxy(),
+      delegate.PassAs<PairingRegistry::Delegate>());
+#else  // defined(OS_WIN)
+  pairing_registry =
       CreatePairingRegistry(io_thread.message_loop_proxy());
+#endif  // !defined(OS_WIN)
 
   // Set up the native messaging channel.
   scoped_ptr<NativeMessagingChannel> channel(
       new NativeMessagingChannel(read_file, write_file));
 
+  // Create the native messaging host.
   scoped_ptr<Me2MeNativeMessagingHost> host(
       new Me2MeNativeMessagingHost(
           needs_elevation,