Allow chrome to become the os default handler for arbitrary protocols on mac/win.

chrome/installer/util/shell_util.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file defines functions that integrate Chrome in Windows shell. These
 // functions can be used by Chrome as well as Chrome installer. All of the
 // work is done by the local functions defined in anonymous namespace in
 // this class.
 
 #include "chrome/installer/util/shell_util.h"
@@ skipping 52 matching lines @@
     entries->push_front(new RegistryEntry(
         chrome_html_prog_id, ShellUtil::kRegUrlProtocol, L""));
     entries->push_front(new RegistryEntry(
         chrome_html_prog_id + ShellUtil::kRegDefaultIcon, icon_path));
     entries->push_front(new RegistryEntry(
         chrome_html_prog_id + ShellUtil::kRegShellOpen, open_cmd));
 
     return true;
   }
 
+  // This method returns a list of the system level registry entries
+  // needed to declare a capability of handling a protocol.
+  static bool GetProtocolCapabilityEntries(BrowserDistribution* dist,
+                                           const std::wstring& chrome_exe,
+                                           const std::wstring& suffix,
+                                           const std::wstring& protocol,
+                                           std::list<RegistryEntry*>* entries) {
+    std::wstring app_name = dist->GetApplicationName() + suffix;
+    std::wstring start_menu_entry(ShellUtil::kRegStartMenuInternet);
+    start_menu_entry.append(L"\\" + app_name);
+
+    std::wstring capabilities(start_menu_entry + L"\\Capabilities");
+
+    std::wstring html_prog_id(ShellUtil::kChromeHTMLProgId);
+    html_prog_id.append(suffix);
+    entries->push_front(new RegistryEntry(capabilities + L"\\URLAssociations",
+        protocol, html_prog_id));
+    return true;
+}
+
+
   // This method returns a list of all the system level registry entries that
   // are needed to register Chromium on the machine.
   static bool GetSystemEntries(BrowserDistribution* dist,
                                const std::wstring& chrome_exe,
                                const std::wstring& suffix,
                                std::list<RegistryEntry*>* entries) {
     std::wstring icon_path = ShellUtil::GetChromeIcon(dist, chrome_exe);
     std::wstring quoted_exe_path = L"\"" + chrome_exe + L"\"";
 
     std::wstring app_name = dist->GetApplicationName() + suffix;
@@ skipping 29 matching lines @@
     entries->push_front(new RegistryEntry(capabilities + L"\\StartMenu",
         L"StartMenuInternet", app_name));
 
     std::wstring html_prog_id(ShellUtil::kChromeHTMLProgId);
     html_prog_id.append(suffix);
     for (int i = 0; ShellUtil::kFileAssociations[i] != NULL; i++) {
       entries->push_front(new RegistryEntry(
           capabilities + L"\\FileAssociations",
           ShellUtil::kFileAssociations[i], html_prog_id));
     }
-    for (int i = 0; ShellUtil::kProtocolAssociations[i] != NULL; i++) {
+    for (int i = 0; ShellUtil::kPotentialProtocolAssociations[i] != NULL;
+        i++) {
       entries->push_front(new RegistryEntry(
           capabilities + L"\\URLAssociations",
-          ShellUtil::kProtocolAssociations[i], html_prog_id));
+          ShellUtil::kPotentialProtocolAssociations[i], html_prog_id));
     }
 
     FilePath chrome_path(chrome_exe);
     std::wstring app_path_key(ShellUtil::kAppPathsRegistryKey);
     file_util::AppendToPath(&app_path_key, chrome_path.BaseName().value());
     entries->push_front(new RegistryEntry(app_path_key, chrome_exe));
     entries->push_front(new RegistryEntry(app_path_key,
         ShellUtil::kAppPathsRegistryPathName, chrome_path.DirName().value()));
 
     // TODO: add chrome to open with list (Bug 16726).
     return true;
   }
 
   // This method returns a list of all the user level registry entries that
+  // are needed to make Chromium the default handler for a protocol.
+  static bool GetUserProtocolEntries(BrowserDistribution* dist,
+                                 const std::wstring& chrome_exe,
+                                 const std::wstring& suffix,
+                                 const std::wstring& protocol,
+                                 const std::wstring& chrome_icon,
+                                 const std::wstring& chrome_open,
+                                 std::list<RegistryEntry*>* entries) {

[xiyuan, 2011/05/24 17:55:20]

nit: please fix args alignment

[benwells, 2011/05/25 08:07:19]

Done.

+    // Protocols associations.
+    std::wstring url_key(ShellUtil::kRegClasses);
+    file_util::AppendToPath(&url_key, protocol);
+
+    // This registry value tells Windows that this 'class' is a URL scheme
+    // so IE, explorer and other apps will route it to our handler.
+    // <root hkey>\Software\Classes\<protocol>\URL Protocol
+    entries->push_front(new RegistryEntry(url_key,
+        ShellUtil::kRegURLProtocol, L""));
+
+    // <root hkey>\Software\Classes\<protocol>\DefaultIcon
+    std::wstring icon_key = url_key + ShellUtil::kRegDefaultIcon;
+    entries->push_front(new RegistryEntry(icon_key, chrome_icon));
+
+    // <root hkey>\Software\Classes\<protocol>\shell\open\command
+    std::wstring shell_key = url_key + ShellUtil::kRegShellOpen;
+    entries->push_front(new RegistryEntry(shell_key, chrome_open));
+
+    // <root hkey>\Software\Classes\<protocol>\shell\open\ddeexec
+    std::wstring dde_key = url_key + L"\\shell\\open\\ddeexec";
+    entries->push_front(new RegistryEntry(dde_key, L""));
+
+    // <root hkey>\Software\Classes\<protocol>\shell\@
+    std::wstring protocol_shell_key = url_key + ShellUtil::kRegShellPath;
+    entries->push_front(new RegistryEntry(protocol_shell_key, L"open"));
+
+    return true;
+  }
+
+  // This method returns a list of all the user level registry entries that
   // are needed to make Chromium default browser.
   static bool GetUserEntries(BrowserDistribution* dist,
                              const std::wstring& chrome_exe,
                              const std::wstring& suffix,
                              std::list<RegistryEntry*>* entries) {
     // File extension associations.
     std::wstring html_prog_id(ShellUtil::kChromeHTMLProgId);
     html_prog_id.append(suffix);
     for (int i = 0; ShellUtil::kFileAssociations[i] != NULL; i++) {
       std::wstring ext_key(ShellUtil::kRegClasses);
       file_util::AppendToPath(&ext_key, ShellUtil::kFileAssociations[i]);
       entries->push_front(new RegistryEntry(ext_key, html_prog_id));
     }
 
     // Protocols associations.
     std::wstring chrome_open = ShellUtil::GetChromeShellOpenCmd(chrome_exe);
     std::wstring chrome_icon = ShellUtil::GetChromeIcon(dist, chrome_exe);
-    for (int i = 0; ShellUtil::kProtocolAssociations[i] != NULL; i++) {
-      std::wstring url_key(ShellUtil::kRegClasses);
-      file_util::AppendToPath(&url_key, ShellUtil::kProtocolAssociations[i]);
-
-      // <root hkey>\Software\Classes\<protocol>\DefaultIcon
-      std::wstring icon_key = url_key + ShellUtil::kRegDefaultIcon;
-      entries->push_front(new RegistryEntry(icon_key, chrome_icon));
-
-      // <root hkey>\Software\Classes\<protocol>\shell\open\command
-      std::wstring shell_key = url_key + ShellUtil::kRegShellOpen;
-      entries->push_front(new RegistryEntry(shell_key, chrome_open));
-
-      // <root hkey>\Software\Classes\<protocol>\shell\open\ddeexec
-      std::wstring dde_key = url_key + L"\\shell\\open\\ddeexec";
-      entries->push_front(new RegistryEntry(dde_key, L""));
-
-      // <root hkey>\Software\Classes\<protocol>\shell\@
-      std::wstring protocol_shell_key = url_key + ShellUtil::kRegShellPath;
-      entries->push_front(new RegistryEntry(protocol_shell_key, L"open"));
+    for (int i = 0; ShellUtil::kBrowserProtocolAssociations[i] != NULL; i++) {
+      GetUserProtocolEntries(dist, chrome_exe, suffix,
+                         ShellUtil::kBrowserProtocolAssociations[i],
+                         chrome_icon, chrome_open, entries);

[xiyuan, 2011/05/24 17:55:20]

nit: should use either 4 spaces indentation or align with first-line args

[benwells, 2011/05/25 08:07:19]

Done.

     }
 
     // start->Internet shortcut.
     std::wstring start_menu(ShellUtil::kRegStartMenuInternet);
     std::wstring app_name = dist->GetApplicationName() + suffix;
     entries->push_front(new RegistryEntry(start_menu, app_name));
     return true;
   }
 
   // Generate work_item tasks required to create current registry entry and
@@ skipping 104 matching lines @@
   RegistryEntry::GetSystemEntries(dist, chrome_exe, suffix, &entries);
   for (std::list<RegistryEntry*>::const_iterator itr = entries.begin();
        itr != entries.end() && registered; ++itr) {
     // We do not need registered = registered && ... since the loop condition
     // is set to exit early.
     registered = (*itr)->ExistsInHKLM();
   }
   return registered;
 }
 
+// This method checks if Chrome is already registered on the local machine
+// for the requested protocol. It just checks the one value required for this.
+bool IsChromeRegisteredForProtocol(BrowserDistribution* dist,
+                                   const std::wstring& chrome_exe,
+                                   const std::wstring& suffix,
+                                   const std::wstring& protocol) {
+  bool registered = true;
+  std::list<RegistryEntry*> entries;
+  STLElementDeleter<std::list<RegistryEntry*>> entries_deleter(&entries);
+  RegistryEntry::GetProtocolCapabilityEntries(dist, chrome_exe, suffix,
+      protocol, &entries);
+  for (std::list<RegistryEntry*>::const_iterator itr = entries.begin();
+       itr != entries.end() && registered; ++itr) {
+    // We do not need registered = registered && ... since the loop condition
+    // is set to exit early.
+    registered = (*itr)->ExistsInHKLM();
+  }
+  return registered;
+}
+
 // This method registers Chrome on Vista by launching an elevated setup.exe.
 // That will show the user the standard Vista elevation prompt. If the user
 // accepts it the new process will make the necessary changes and return SUCCESS
 // that we capture and return.
+// If protocol is non-empty we will also register Chrome as being capable of
+// handling the protocol.
 bool ElevateAndRegisterChrome(BrowserDistribution* dist,
                               const std::wstring& chrome_exe,
-                              const std::wstring& suffix) {
+                              const std::wstring& suffix,
+                              const std::wstring& protocol) {
   FilePath exe_path =
       FilePath::FromWStringHack(chrome_exe).DirName()
           .Append(installer::kSetupExe);
   if (!file_util::PathExists(exe_path)) {
     HKEY reg_root = InstallUtil::IsPerUserInstall(chrome_exe.c_str()) ?
         HKEY_CURRENT_USER : HKEY_LOCAL_MACHINE;
     RegKey key(reg_root, dist->GetUninstallRegPath().c_str(), KEY_READ);
     std::wstring uninstall_string;
     key.ReadValue(installer::kUninstallStringField, &uninstall_string);
     CommandLine command_line = CommandLine::FromString(uninstall_string);
     exe_path = command_line.GetProgram();
   }
 
   if (file_util::PathExists(exe_path)) {
     CommandLine cmd(exe_path);
     cmd.AppendSwitchNative(installer::switches::kRegisterChromeBrowser,
                            chrome_exe);
     if (!suffix.empty()) {
       cmd.AppendSwitchNative(
           installer::switches::kRegisterChromeBrowserSuffix, suffix);
     }
 
     CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
     if (browser_command_line.HasSwitch(switches::kChromeFrame)) {
       cmd.AppendSwitch(installer::switches::kChromeFrame);
     }
 
+    if (!protocol.empty()) {
+      cmd.AppendSwitchNative(
+        installer::switches::kRegisterURLProtocol, protocol);
+    }
+
     DWORD ret_val = 0;
     InstallUtil::ExecuteExeAsAdmin(cmd, &ret_val);
     if (ret_val == 0)
       return true;
   }
   return false;
 }
 
 // This method tries to figure out if another user has already registered her
 // own copy of Chrome so that we can avoid overwriting it and append current
@@ skipping 45 matching lines @@
         return false;
       else
         one_mismatch = true;
     }
   }
   return true;
 }
 
 }  // namespace
 
-
+const wchar_t* ShellUtil::kRegURLProtocol = L"URL Protocol";

[grt (UTC plus 2), 2011/05/24 20:27:53]

Remove this and use kRegUrlProtocol (defined below).

[benwells, 2011/05/25 08:07:19]

Done.

 const wchar_t* ShellUtil::kRegDefaultIcon = L"\\DefaultIcon";
 const wchar_t* ShellUtil::kRegShellPath = L"\\shell";
 const wchar_t* ShellUtil::kRegShellOpen = L"\\shell\\open\\command";
 const wchar_t* ShellUtil::kRegStartMenuInternet =
     L"Software\\Clients\\StartMenuInternet";
 const wchar_t* ShellUtil::kRegClasses = L"Software\\Classes";
 const wchar_t* ShellUtil::kRegRegisteredApplications =
     L"Software\\RegisteredApplications";
 const wchar_t* ShellUtil::kRegVistaUrlPrefs =
     L"Software\\Microsoft\\Windows\\Shell\\Associations\\UrlAssociations\\"
     L"http\\UserChoice";
 const wchar_t* ShellUtil::kAppPathsRegistryKey =
     L"Software\\Microsoft\\Windows\\CurrentVersion\\App Paths";
 const wchar_t* ShellUtil::kAppPathsRegistryPathName = L"Path";
 
 #if defined(GOOGLE_CHROME_BUILD)
 const wchar_t* ShellUtil::kChromeHTMLProgId = L"ChromeHTML";
 const wchar_t* ShellUtil::kChromeHTMLProgIdDesc = L"Chrome HTML Document";
 #else
 const wchar_t* ShellUtil::kChromeHTMLProgId = L"ChromiumHTML";
 const wchar_t* ShellUtil::kChromeHTMLProgIdDesc = L"Chromium HTML Document";
 #endif
 
 const wchar_t* ShellUtil::kFileAssociations[] = {L".htm", L".html", L".shtml",
     L".xht", L".xhtml", NULL};
-const wchar_t* ShellUtil::kProtocolAssociations[] = {L"ftp", L"http", L"https",
-    NULL};
+const wchar_t* ShellUtil::kBrowserProtocolAssociations[] = {L"ftp", L"http",
+    L"https", NULL};
+const wchar_t* ShellUtil::kPotentialProtocolAssociations[] = {L"ftp", L"http",
+    L"https", L"mailto", L"webcal", NULL};
 const wchar_t* ShellUtil::kRegUrlProtocol = L"URL Protocol";
 
 bool ShellUtil::AdminNeededForRegistryCleanup(BrowserDistribution* dist,
                                               const std::wstring& suffix) {
   bool cleanup_needed = false;
   std::list<RegistryEntry*> entries;
   STLElementDeleter<std::list<RegistryEntry*>> entries_deleter(&entries);
   RegistryEntry::GetProgIdEntries(dist, L"chrome.exe", suffix, &entries);
   RegistryEntry::GetSystemEntries(dist, L"chrome.exe", suffix, &entries);
   for (std::list<RegistryEntry*>::const_iterator itr = entries.begin();
@@ skipping 192 matching lines @@
   if (!dist->CanSetAsDefault())
     return false;
 
   ShellUtil::RegisterChromeBrowser(dist, chrome_exe, L"", elevate_if_not_admin);
 
   bool ret = true;
   // First use the new "recommended" way on Vista to make Chrome default
   // browser.
   if (base::win::GetVersion() >= base::win::VERSION_VISTA) {
     VLOG(1) << "Registering Chrome as default browser on Vista.";
-    IApplicationAssociationRegistration* pAAR;
+      IApplicationAssociationRegistration* pAAR;

[xiyuan, 2011/05/24 17:55:20]

nit: please fix indentation

[xiyuan, 2011/05/24 17:55:20]

suggest to use ScopedComPtr

[benwells, 2011/05/25 08:07:19]

Done.

[benwells, 2011/05/25 08:07:19]

Done.

     HRESULT hr = CoCreateInstance(CLSID_ApplicationAssociationRegistration,
         NULL, CLSCTX_INPROC, __uuidof(IApplicationAssociationRegistration),
         (void**)&pAAR);
     if (SUCCEEDED(hr)) {
       std::wstring app_name = dist->GetApplicationName();
       std::wstring suffix;
       if (ShellUtil::GetUserSpecificDefaultBrowserSuffix(dist, &suffix))
         app_name += suffix;
 
-      hr = pAAR->SetAppAsDefaultAll(app_name.c_str());
+      for (int i = 0; ShellUtil::kBrowserProtocolAssociations[i] != NULL; i++) {
+        if (SUCCEEDED(hr)) {

[xiyuan, 2011/05/24 17:55:20]

Think you should break out of loop when !SUCCEEDED(hr). Otherwise, the failure
is ignored. You can put SUCCEEDED(hr) as part of the loop end condition.

[benwells, 2011/05/25 08:07:19]

Done.

[grt (UTC plus 2), 2011/05/25 14:35:45]

I wonder about this: why not make registration a best-effort deal?  If the third
call to SetAppAsDefault fails, you don't go back and un-set the first two, so
why not continue in the face of error and do the best you can?  In this case,
you should consider whether it's better to return true if any changes where made
("i did something!") or only if all desired changes were made ("do ALL the
registrations!").  And, of course, document the function accordingly.

[benwells, 2011/05/26 00:23:04]

I have left the return value as is as it is consistent with
ShellIntegration::IsDefaultBrowser, which returns 'no' if any of these
registrations are missing. Ideally if there is a failure we would attempt to
undo anything we've done, I've added a TODO and http://crbug.com/83970 for this.
This is documented in shell_util.h.

Alternatively it might be better to keep going and do the best we can, this
might set as default successfully as far as the user is concerned (e.g.
protocols handled but not files) but would leave the UI inconsistent. Given that
this shouldn't happen (i.e. if you've registered your capability successfully
you should be able to become default) it seems better to keep the UI consistent
with the state.

If there are further changes to make here / further discussion perhaps we can
take it to http://crbug.com/83970 if it isn't critical to address now.

+          hr = pAAR->SetAppAsDefault(app_name.c_str(),
+              ShellUtil::kBrowserProtocolAssociations[i],
+              AT_URLPROTOCOL);
+        }
+      }
+
+      for (int i = 0; ShellUtil::kFileAssociations[i] != NULL; i++) {
+        if (SUCCEEDED(hr)) {

[xiyuan, 2011/05/24 17:55:20]

similarly here, need to get out of loop when failed.

[benwells, 2011/05/25 08:07:19]

Done.

+          hr = pAAR->SetAppAsDefault(app_name.c_str(),
+              ShellUtil::kFileAssociations[i], AT_FILEEXTENSION);
+        }
+      }
       pAAR->Release();
     }
     if (!SUCCEEDED(hr)) {
       ret = false;
       LOG(ERROR) << "Could not make Chrome default browser.";

[grt (UTC plus 2), 2011/05/24 20:27:53]

How about logging hr so that we get some idea of why registration failed?

[benwells, 2011/05/25 08:07:19]

Done.

     }
   }
 
   // Now use the old way to associate Chrome with supported protocols and file
   // associations. This should not be required on Vista but since some
   // applications still read Software\Classes\http key directly, we have to do
   // this on Vista also.
 
   std::list<RegistryEntry*> entries;
   STLElementDeleter<std::list<RegistryEntry*>> entries_deleter(&entries);
@@ skipping 10 matching lines @@
   if ((shell_change & ShellUtil::SYSTEM_LEVEL) &&
       !AddRegistryEntries(HKEY_LOCAL_MACHINE, entries))
     ret = false;
 
   // Send Windows notification event so that it can update icons for
   // file associations.
   SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST, NULL, NULL);
   return ret;
 }
 
+bool ShellUtil::MakeChromeDefaultProtocolClient(BrowserDistribution* dist,
+                                                const std::wstring& chrome_exe,
+                                                const std::wstring& protocol) {
+  if (!dist->CanSetAsDefault())
+    return false;
+
+  ShellUtil::RegisterChromeForProtocol(dist, chrome_exe, L"", protocol, true);
+
+  bool ret = true;
+  // First use the new "recommended" way on Vista to make Chrome default
+  // protocol handler.
+  if (base::win::GetVersion() >= base::win::VERSION_VISTA) {
+    VLOG(1) << "Registering Chrome as default handler for " << protocol
+            << " on Vista.";
+      IApplicationAssociationRegistration* pAAR;

[xiyuan, 2011/05/24 17:55:20]

similar to above, please fix indentation and suggest to use ScopedComPtr

[benwells, 2011/05/25 08:07:19]

Done.

+    HRESULT hr = CoCreateInstance(CLSID_ApplicationAssociationRegistration,
+        NULL, CLSCTX_INPROC, __uuidof(IApplicationAssociationRegistration),
+        (void**)&pAAR);
+    if (SUCCEEDED(hr)) {
+      std::wstring app_name = dist->GetApplicationName();
+      std::wstring suffix;
+      if (ShellUtil::GetUserSpecificDefaultBrowserSuffix(dist, &suffix))
+        app_name += suffix;
+
+      hr = pAAR->SetAppAsDefault(app_name.c_str(), protocol.c_str(),
+                                 AT_URLPROTOCOL);
+      pAAR->Release();
+    }
+    if (!SUCCEEDED(hr)) {
+      ret = false;
+      LOG(ERROR) << "Could not make Chrome default protocol client (Vista).";
+    }
+  }
+
+  // Now use the old way to associate Chrome with the desired protocol. This
+  // should not be required on Vista but since some applications still read
+  // Software\Classes\http key directly, we have to do this on Vista also.
+
+  std::list<RegistryEntry*> entries;
+  STLElementDeleter<std::list<RegistryEntry*>> entries_deleter(&entries);
+  std::wstring suffix;
+  if (!GetUserSpecificDefaultBrowserSuffix(dist, &suffix))
+    suffix = L"";
+  std::wstring chrome_open = ShellUtil::GetChromeShellOpenCmd(chrome_exe);
+  std::wstring chrome_icon = ShellUtil::GetChromeIcon(dist, chrome_exe);
+  RegistryEntry::GetUserProtocolEntries(dist, chrome_exe, suffix, protocol,
+                                        chrome_icon, chrome_open, &entries);
+  // Change the default protocol handler for current user.
+  if (!AddRegistryEntries(HKEY_CURRENT_USER, entries)) {
+      ret = false;
+      LOG(ERROR) << "Could not make Chrome default protocol client (XP).";
+  }
+
+  return ret;
+}
+
 bool ShellUtil::RegisterChromeBrowser(BrowserDistribution* dist,
                                       const std::wstring& chrome_exe,
                                       const std::wstring& unique_suffix,
                                       bool elevate_if_not_admin) {
   if (!dist->CanSetAsDefault())
     return false;
 
   // First figure out we need to append a suffix to the registry entries to
   // make them unique.
   std::wstring suffix;
@@ skipping 14 matching lines @@
     std::list<RegistryEntry*> entries;
     STLElementDeleter<std::list<RegistryEntry*>> entries_deleter(&entries);
     RegistryEntry::GetProgIdEntries(dist, chrome_exe, suffix, &entries);
     RegistryEntry::GetSystemEntries(dist, chrome_exe, suffix, &entries);
     return AddRegistryEntries(HKEY_LOCAL_MACHINE, entries);
   }
 
   // If user is not an admin and OS is Vista, try to elevate and register.
   if (elevate_if_not_admin &&
       base::win::GetVersion() >= base::win::VERSION_VISTA &&
-      ElevateAndRegisterChrome(dist, chrome_exe, suffix))
+      ElevateAndRegisterChrome(dist, chrome_exe, suffix, L""))
     return true;
 
   // If we got to this point then all we can do is create ProgIds under HKCU
   // on XP as well as Vista.
   std::list<RegistryEntry*> entries;
   STLElementDeleter<std::list<RegistryEntry*>> entries_deleter(&entries);
   RegistryEntry::GetProgIdEntries(dist, chrome_exe, L"", &entries);
   return AddRegistryEntries(HKEY_CURRENT_USER, entries);
 }
 
+bool ShellUtil::RegisterChromeForProtocol(BrowserDistribution* dist,
+                                          const std::wstring& chrome_exe,
+                                          const std::wstring& unique_suffix,
+                                          const std::wstring& protocol,
+                                          bool elevate_if_not_admin) {
+  if (!dist->CanSetAsDefault())
+    return false;
+
+  // Figure out we need to append a suffix to the registry entries to
+  // make them unique.
+  std::wstring suffix;
+  if (!unique_suffix.empty()) {
+    suffix = unique_suffix;
+  } else if (InstallUtil::IsPerUserInstall(chrome_exe.c_str()) &&
+             !GetUserSpecificDefaultBrowserSuffix(dist, &suffix) &&
+             !AnotherUserHasDefaultBrowser(dist, chrome_exe)) {
+    suffix = L"";
+  }
+
+  // Check if Chromium is already registered with this suffix.
+  if (IsChromeRegisteredForProtocol(dist, chrome_exe, suffix, protocol))
+    return true;
+
+  if (IsUserAnAdmin()) {
+    // We can do this operation directly.
+    // If we're not registered at all, try to register. If that fails
+    // we should give up.
+    if (!IsChromeRegistered(dist, chrome_exe, suffix) &&
+        !RegisterChromeBrowser(dist, chrome_exe, suffix, false)) {
+      return false;
+    }
+
+    // Write in the capabillity for the protocol.
+    std::list<RegistryEntry*> entries;
+    STLElementDeleter<std::list<RegistryEntry*>> entries_deleter(&entries);
+    RegistryEntry::GetProtocolCapabilityEntries(dist, chrome_exe, suffix,
+        protocol, &entries);
+    return AddRegistryEntries(HKEY_LOCAL_MACHINE, entries);
+

[xiyuan, 2011/05/24 17:55:20]

nit: nuke the empty line

[benwells, 2011/05/25 08:07:19]

Done.

+  } else if (elevate_if_not_admin &&
+      base::win::GetVersion() >= base::win::VERSION_VISTA) {

[grt (UTC plus 2), 2011/05/24 20:27:53]

align with the 'e' in "(elevate" above

[benwells, 2011/05/25 08:07:19]

Done.

+    // Elevate to do the whole job
+    return ElevateAndRegisterChrome(dist, chrome_exe, suffix, protocol);
+  } else {
+    // we need admin rights to register our capability. If we don't
+    // have them and can't elevate, give up.
+    return false;
+  }
+}
+
 bool ShellUtil::RemoveChromeDesktopShortcut(BrowserDistribution* dist,
                                             int shell_change, bool alternate) {
   std::wstring shortcut_name;
   if (!ShellUtil::GetChromeShortcutName(dist, &shortcut_name, alternate))
     return false;
 
   bool ret = true;
   if (shell_change & ShellUtil::CURRENT_USER) {
     FilePath shortcut_path;
     if (ShellUtil::GetDesktopPath(false, &shortcut_path)) {
@@ skipping 76 matching lines @@
         chrome_exe.c_str(),                // target
         shortcut.c_str(),                  // shortcut
         chrome_path.c_str(),               // working dir
         NULL,                              // arguments
         description.c_str(),               // description
         chrome_exe.c_str(),                // icon file
         icon_index,                        // icon index
         dist->GetBrowserAppId().c_str());  // app id
   }
 }