Windows install_static refactor.

chrome/install_static/install_util.cc

 // Copyright 2014 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.
 
 #include "chrome/install_static/install_util.h"
 
 #include <windows.h>
 #include <assert.h>
+#include <string.h>
+
 #include <algorithm>
-#include <iostream>
-#include <iterator>
 #include <memory>
 #include <sstream>
 
+#include "chrome/install_static/install_details.h"
+#include "chrome/install_static/install_modes.h"
 #include "chrome_elf/nt_registry/nt_registry.h"
 
 namespace install_static {
 
 ProcessType g_process_type = ProcessType::UNINITIALIZED;
 
+const wchar_t kRegValueChromeStatsSample[] = L"UsageStatsInSample";
+
 // TODO(ananta)
 // http://crbug.com/604923
 // The constants defined in this file are also defined in chrome/installer and
 // other places. we need to unify them.
-
-// Chrome channel display names.
-const wchar_t kChromeChannelUnknown[] = L"unknown";
-const wchar_t kChromeChannelCanary[] = L"canary";
-const wchar_t kChromeChannelDev[] = L"dev";
-const wchar_t kChromeChannelBeta[] = L"beta";
-const wchar_t kChromeChannelStable[] = L"";
-const wchar_t kChromeChannelStableExplicit[] = L"stable";
-const wchar_t kRegApField[] = L"ap";
-
-#if defined(GOOGLE_CHROME_BUILD)
-const wchar_t kRegPathClientState[] = L"Software\\Google\\Update\\ClientState";
-const wchar_t kRegPathClientStateMedium[] =
-    L"Software\\Google\\Update\\ClientStateMedium";
-const wchar_t kRegPathChromePolicy[] = L"SOFTWARE\\Policies\\Google\\Chrome";
-#else
-const wchar_t kRegPathClientState[] =
-    L"Software\\Chromium\\Update\\ClientState";
-const wchar_t kRegPathClientStateMedium[] =
-    L"Software\\Chromium\\Update\\ClientStateMedium";
-const wchar_t kRegPathChromePolicy[] = L"SOFTWARE\\Policies\\Chromium";
-#endif
-
-const wchar_t kRegValueChromeStatsSample[] = L"UsageStatsInSample";
-const wchar_t kRegValueUsageStats[] = L"usagestats";
-const wchar_t kUninstallArgumentsField[] = L"UninstallArguments";
-const wchar_t kMetricsReportingEnabled[] = L"MetricsReportingEnabled";
-
-const wchar_t kAppGuidCanary[] = L"{4ea16ac7-fd5a-47c3-875b-dbf4a2008c20}";
-const wchar_t kAppGuidGoogleChrome[] =
-    L"{8A69D345-D564-463c-AFF1-A69D9E530F96}";
-const wchar_t kAppGuidGoogleBinaries[] =
-    L"{4DC8B4CA-1BDA-483e-B5FA-D3C12E15B62D}";
-
 const wchar_t kHeadless[] = L"CHROME_HEADLESS";
 const wchar_t kShowRestart[] = L"CHROME_CRASHED";
 const wchar_t kRestartInfo[] = L"CHROME_RESTART";
 const wchar_t kRtlLocale[] = L"RIGHT_TO_LEFT";
 
 const char kGpuProcess[] = "gpu-process";
 const char kPpapiPluginProcess[] = "ppapi";
 const char kRendererProcess[] = "renderer";
 const char kUtilityProcess[] = "utility";
 const char kProcessType[] = "type";
 const char kCrashpadHandler[] = "crashpad-handler";
 
 namespace {
 
 // TODO(ananta)
 // http://crbug.com/604923
+// The constants defined in this file are also defined in chrome/installer and
+// other places. we need to unify them.
+// Chrome channel display names.
+constexpr wchar_t kChromeChannelUnknown[] = L"unknown";
+constexpr wchar_t kChromeChannelDev[] = L"dev";
+constexpr wchar_t kChromeChannelBeta[] = L"beta";
+constexpr wchar_t kChromeChannelStableExplicit[] = L"stable";
+
+// TODO(ananta)
+// http://crbug.com/604923
 // These constants are defined in the chrome/installer directory as well. We
 // need to unify them.
-#if defined(GOOGLE_CHROME_BUILD)
-const wchar_t kSxSSuffix[] = L" SxS";
-const wchar_t kGoogleChromeInstallSubDir1[] = L"Google";
-const wchar_t kGoogleChromeInstallSubDir2[] = L"Chrome";
-#else
-const wchar_t kChromiumInstallSubDir[] = L"Chromium";
-#endif  // defined(GOOGLE_CHROME_BUILD)
+constexpr wchar_t kRegValueAp[] = L"ap";
+constexpr wchar_t kRegValueUsageStats[] = L"usagestats";
+constexpr wchar_t kMetricsReportingEnabled[] = L"MetricsReportingEnabled";
 
-const wchar_t kUserDataDirname[] = L"User Data";
-const wchar_t kBrowserCrashDumpMetricsSubKey[] = L"\\BrowserCrashDumpAttempts";
-
-const wchar_t kRegPathGoogleUpdate[] = L"Software\\Google\\Update";
-const wchar_t kRegGoogleUpdateVersion[] = L"version";
+constexpr wchar_t kUserDataDirname[] = L"User Data";
+constexpr wchar_t kBrowserCrashDumpMetricsSubKey[] =
+    L"\\BrowserCrashDumpAttempts";
 
 void Trace(const wchar_t* format_string, ...) {
   static const int kMaxLogBufferSize = 1024;
   static wchar_t buffer[kMaxLogBufferSize] = {};
 
   va_list args = {};
 
   va_start(args, format_string);
   vswprintf(buffer, kMaxLogBufferSize, format_string, args);
   OutputDebugStringW(buffer);
@@ skipping 71 matching lines @@
     uint32_t size = 0;
     BOOL r = ::VerQueryValueW(version_resource, sub_block, &value, &size);
     if (r && value) {
       value_str->assign(static_cast<wchar_t*>(value));
       return true;
     }
   }
   return false;
 }
 
-// Returns the executable path for the current process.
-std::wstring GetCurrentProcessExePath() {
-  wchar_t exe_path[MAX_PATH];
-  if (::GetModuleFileName(nullptr, exe_path, MAX_PATH) == 0)
-    return std::wstring();
-  return exe_path;
-}
-
 bool RecursiveDirectoryCreate(const std::wstring& full_path) {
   // If the path exists, we've succeeded if it's a directory, failed otherwise.
   const wchar_t* full_path_str = full_path.c_str();
   DWORD file_attributes = ::GetFileAttributes(full_path_str);
   if (file_attributes != INVALID_FILE_ATTRIBUTES) {
     if ((file_attributes & FILE_ATTRIBUTE_DIRECTORY) != 0) {
       Trace(L"%hs( %ls directory exists )\n", __func__, full_path_str);
       return true;
     }
     Trace(L"%hs( %ls directory conflicts with an existing file. )\n", __func__,
@@ skipping 29 matching lines @@
       } else {
         Trace(L"Failed to create directory %ls, last error is %d\n",
               full_path_str, error_code);
         return false;
       }
     }
   }
   return true;
 }
 
+// Appends "[kCompanyPathName\]kProductPathName[install_suffix]" to |path|,
+// returning a reference to |path|.
+std::wstring& AppendChromeInstallSubDirectory(std::wstring* path,
+                                              bool include_suffix) {
+  if (*kCompanyPathName) {
+    path->append(kCompanyPathName);
+    path->push_back(L'\\');
+  }
+  path->append(kProductPathName, kProductPathNameLength);
+  if (!include_suffix)
+    return *path;
+  return path->append(InstallDetails::Get().install_suffix());
+}
+
 std::wstring GetChromeInstallRegistryPath() {
   std::wstring registry_path = L"Software\\";
-  registry_path += GetChromeInstallSubDirectory();
-  return registry_path;
-}
-
-bool GetCollectStatsConsentImpl(const std::wstring& exe_path) {
-  bool enabled = true;
-
-  if (ReportingIsEnforcedByPolicy(&enabled))
-    return enabled;
-
-  bool system_install = IsSystemInstall(exe_path.c_str());
-  std::wstring app_guid;
-
-  if (IsSxSChrome(exe_path.c_str())) {
-    app_guid = kAppGuidCanary;
-  } else {
-    app_guid = IsMultiInstall(system_install) ? kAppGuidGoogleBinaries
-                                              : kAppGuidGoogleChrome;
-  }
-
-  DWORD out_value = 0;
-
-  // If system_install, first try kRegPathClientStateMedium.
-  std::wstring full_key_path(kRegPathClientStateMedium);
-  full_key_path.append(1, L'\\');
-  full_key_path.append(app_guid);
-  if (system_install &&
-      nt::QueryRegValueDWORD(nt::HKLM, nt::WOW6432, full_key_path.c_str(),
-                             kRegValueUsageStats, &out_value))
-    return (out_value == 1);
-
-  // Second, try kRegPathClientState.
-  full_key_path = kRegPathClientState;
-  full_key_path.append(1, L'\\');
-  full_key_path.append(app_guid);
-  return (nt::QueryRegValueDWORD((system_install ? nt::HKLM : nt::HKCU),
-                                 nt::WOW6432, full_key_path.c_str(),
-                                 kRegValueUsageStats, &out_value) &&
-          out_value == 1);
+  return AppendChromeInstallSubDirectory(&registry_path,
+                                         true /* include_suffix */);
 }
 
 // Returns true if the |source| string matches the |pattern|. The pattern
 // may contain wildcards like '?' which matches one character or a '*'
 // which matches 0 or more characters.
 // Please note that pattern matches the whole string. If you want to find
 // something in the middle of the string then you need to specify the pattern
 // as '*xyz*'.
 // |source_index| is the index of the current character being matched in
 // |source|.
@@ skipping 58 matching lines @@
   return kWhiteSpaces;
 }
 
 // Trim whitespaces from left & right
 template <class StringType>
 void TrimT(StringType* str) {
   str->erase(str->find_last_not_of(GetWhiteSpacesForType<StringType>()) + 1);
   str->erase(0, str->find_first_not_of(GetWhiteSpacesForType<StringType>()));
 }
 
-bool IsValidNumber(const std::string& str) {
-  if (str.empty())
-    return false;
-  return std::all_of(str.begin(), str.end(), ::isdigit);
-}
-
 // Tokenizes a string based on a single character delimiter.
 template <class StringType>
 std::vector<StringType> TokenizeStringT(
     const StringType& str,
     typename StringType::value_type delimiter,
     bool trim_spaces) {
   std::vector<StringType> tokens;
   std::basic_istringstream<typename StringType::value_type> buffer(str);
   for (StringType token; std::getline(buffer, token, delimiter);) {
     if (trim_spaces)
       TrimT<StringType>(&token);
     tokens.push_back(token);
   }
   return tokens;
 }
 
+std::wstring ChannelFromAdditionalParameters(const InstallConstants& mode,
+                                             bool system_level,
+                                             bool binaries) {
+  assert(kUseGoogleUpdateIntegration);
+  // InitChannelInfo in google_update_settings.cc only reports a failure in the
+  // case of multi-install Chrome where the binaries' ClientState key exists,
+  // but that the "ap" value therein cannot be read due to some reason *other*
+  // than it not being present. This should be exceedingly rare. For
+  // simplicity's sake, use an empty |value| in case of any error whatsoever
+  // here.
+  std::wstring value;
+  nt::QueryRegValueSZ(system_level ? nt::HKLM : nt::HKCU, nt::WOW6432,
+                      (binaries ? GetBinariesClientStateKeyPath()
+                                : GetClientStateKeyPath(mode.app_guid))
+                          .c_str(),
+                      kRegValueAp, &value);
+
+  static constexpr wchar_t kChromeChannelBetaPattern[] = L"1?1-*";
+  static constexpr wchar_t kChromeChannelBetaX64Pattern[] = L"*x64-beta*";
+  static constexpr wchar_t kChromeChannelDevPattern[] = L"2?0-d*";
+  static constexpr wchar_t kChromeChannelDevX64Pattern[] = L"*x64-dev*";
+
+  std::transform(value.begin(), value.end(), value.begin(), ::tolower);
+
+  // Empty channel names or those containing "stable" should be reported as
+  // an empty string.
+  std::wstring channel_name;
+  if (value.empty() ||
+      (value.find(kChromeChannelStableExplicit) != std::wstring::npos)) {
+  } else if (MatchPattern(value, kChromeChannelDevPattern) ||
+             MatchPattern(value, kChromeChannelDevX64Pattern)) {
+    channel_name.assign(kChromeChannelDev);
+  } else if (MatchPattern(value, kChromeChannelBetaPattern) ||
+             MatchPattern(value, kChromeChannelBetaX64Pattern)) {
+    channel_name.assign(kChromeChannelBeta);
+  }
+  // Else report values with garbage as stable since they will match the stable
+  // rules in the update configs. ChannelInfo::GetChannelName painstakingly
+  // strips off known modifiers (e.g., "-multi-full") to see if the empty string
+  // remains, returning channel "unknown" if not. This differs here in that some
+  // clients will tag crashes as "stable" rather than "unknown" via this
+  // codepath, but it is an accurate reflection of which update channel the
+  // client is on according to the server-side rules.
+
+  return channel_name;
+}
+
 }  // namespace
 
-bool IsSxSChrome(const wchar_t* exe_path) {
-  return ::wcsstr(exe_path, L"Chrome SxS\\Application") != nullptr;
+bool IsSystemInstall() {
+  return InstallDetails::Get().system_level();
 }
 
-bool IsSystemInstall(const wchar_t* exe_path) {
-  wchar_t program_dir[MAX_PATH] = {};
-  DWORD ret = ::GetEnvironmentVariable(L"PROGRAMFILES", program_dir, MAX_PATH);
-  if (ret && ret < MAX_PATH && !::wcsnicmp(exe_path, program_dir, ret)) {
-    return true;
-  }
-
-  ret = ::GetEnvironmentVariable(L"PROGRAMFILES(X86)", program_dir, MAX_PATH);
-  if (ret && ret < MAX_PATH && !::wcsnicmp(exe_path, program_dir, ret)) {
-    return true;
-  }
-
-  return false;
-}
-
-bool IsMultiInstall(bool is_system_install) {
-  std::wstring args;
-
-  std::wstring full_key_path(kRegPathClientState);
-  full_key_path.append(1, L'\\');
-  full_key_path.append(kAppGuidGoogleChrome);
-  if (!nt::QueryRegValueSZ((is_system_install ? nt::HKLM : nt::HKCU),
-                           nt::WOW6432, full_key_path.c_str(),
-                           kUninstallArgumentsField, &args))
-    return false;
-
-  return (args.find(L"--multi-install") != std::wstring::npos);
+bool IsMultiInstall() {
+  return InstallDetails::Get().multi_install();
 }
 
 bool GetCollectStatsConsent() {
-  return GetCollectStatsConsentImpl(GetCurrentProcessExePath());
-}
+  bool enabled = true;
 
-bool GetCollectStatsConsentForTesting(const std::wstring& exe_path) {
-  return GetCollectStatsConsentImpl(exe_path);
+  if (ReportingIsEnforcedByPolicy(&enabled))
+    return enabled;
+
+  const bool system_install = IsSystemInstall();
+
+  DWORD out_value = 0;
+
+  // If system_install, first try ClientStateMedium in HKLM.
+  if (system_install &&
+      nt::QueryRegValueDWORD(
+          nt::HKLM, nt::WOW6432,
+          InstallDetails::Get().GetClientStateMediumKeyPath(true).c_str(),
+          kRegValueUsageStats, &out_value)) {
+    return (out_value == 1);
+  }
+
+  // Second, try ClientState.
+  return (nt::QueryRegValueDWORD(
+              system_install ? nt::HKLM : nt::HKCU, nt::WOW6432,
+              InstallDetails::Get().GetClientStateKeyPath(true).c_str(),
+              kRegValueUsageStats, &out_value) &&
+          out_value == 1);
 }
 
 bool GetCollectStatsInSample() {
   std::wstring registry_path = GetChromeInstallRegistryPath();
 
   DWORD out_value = 0;
   if (!nt::QueryRegValueDWORD(nt::HKCU, nt::WOW6432, registry_path.c_str(),
                               kRegValueChromeStatsSample, &out_value)) {
     // If reading the value failed, treat it as though sampling isn't in effect,
     // implicitly meaning this install is in the sample.
     return true;
   }
   return out_value == 1;
 }
 
 bool SetCollectStatsInSample(bool in_sample) {
   std::wstring registry_path = GetChromeInstallRegistryPath();
 
   HANDLE key_handle = INVALID_HANDLE_VALUE;
   if (!nt::CreateRegKey(nt::HKCU, registry_path.c_str(),
                         KEY_SET_VALUE | KEY_WOW64_32KEY, &key_handle)) {
-    nt::CloseRegKey(key_handle);
     return false;
   }
 
-  return nt::SetRegValueDWORD(key_handle, kRegValueChromeStatsSample,
-                              in_sample ? 1 : 0);
+  bool success = nt::SetRegValueDWORD(key_handle, kRegValueChromeStatsSample,
+                                      in_sample ? 1 : 0);
+  nt::CloseRegKey(key_handle);
+  return success;
 }
 
 bool ReportingIsEnforcedByPolicy(bool* crash_reporting_enabled) {
+  std::wstring policies_path = L"SOFTWARE\\Policies\\";
+  AppendChromeInstallSubDirectory(&policies_path, false /* !include_suffix */);
   DWORD value = 0;
 
   // First, try HKLM.
-  if (nt::QueryRegValueDWORD(nt::HKLM, nt::NONE, kRegPathChromePolicy,
+  if (nt::QueryRegValueDWORD(nt::HKLM, nt::NONE, policies_path.c_str(),
                              kMetricsReportingEnabled, &value)) {
     *crash_reporting_enabled = (value != 0);
     return true;
   }
 
   // Second, try HKCU.
-  if (nt::QueryRegValueDWORD(nt::HKCU, nt::NONE, kRegPathChromePolicy,
+  if (nt::QueryRegValueDWORD(nt::HKCU, nt::NONE, policies_path.c_str(),
                              kMetricsReportingEnabled, &value)) {
     *crash_reporting_enabled = (value != 0);
     return true;
   }
 
   return false;
 }
 
 void InitializeProcessType() {
   assert(g_process_type == ProcessType::UNINITIALIZED);
@@ skipping 16 matching lines @@
 
   g_process_type = ProcessType::BROWSER_PROCESS;
 }
 
 bool IsNonBrowserProcess() {
   assert(g_process_type != ProcessType::UNINITIALIZED);
   return g_process_type == ProcessType::NON_BROWSER_PROCESS;
 }
 
 bool GetDefaultUserDataDirectory(std::wstring* result) {
-  static const wchar_t kLocalAppData[] = L"%LOCALAPPDATA%";
+  // This environment variable should be set on Windows Vista and later
+  // (https://msdn.microsoft.com/library/windows/desktop/dd378457.aspx).
+  std::wstring user_data_dir = GetEnvironmentString16(L"LOCALAPPDATA");
 
-  std::unique_ptr<wchar_t> user_data_dir_path;
-
-  // This environment variable should be set on Windows 7 and up.
-  // If we fail to find this variable then we default to the temporary files
-  // path.
-  DWORD size = ::ExpandEnvironmentStrings(kLocalAppData, nullptr, 0);
-  if (size) {
-    user_data_dir_path.reset(new wchar_t[size]);
-    if (::ExpandEnvironmentStrings(kLocalAppData, user_data_dir_path.get(),
-                                   size) != size) {
-      user_data_dir_path.reset();
-    }
-  }
-  // We failed to find the %LOCALAPPDATA% folder. Fallback to the temporary
-  // files path. If we fail to find this we bail.
-  if (!user_data_dir_path.get()) {
-    size = ::GetTempPath(0, nullptr);
+  if (user_data_dir.empty()) {
+    // LOCALAPPDATA was not set; fallback to the temporary files path.
+    DWORD size = ::GetTempPath(0, nullptr);
     if (!size)
       return false;
-    user_data_dir_path.reset(new wchar_t[size + 1]);
-    if (::GetTempPath(size + 1, user_data_dir_path.get()) != size)
+    user_data_dir.resize(size + 1);
+    size = ::GetTempPath(size + 1, &user_data_dir[0]);
+    if (!size || size >= user_data_dir.size())
       return false;
+    user_data_dir.resize(size);
   }
 
-  std::wstring install_sub_directory = GetChromeInstallSubDirectory();
-
-  *result = user_data_dir_path.get();
+  result->swap(user_data_dir);
   if ((*result)[result->length() - 1] != L'\\')
-    result->append(L"\\");
-  result->append(install_sub_directory);
-  result->append(L"\\");
+    result->push_back(L'\\');
+  AppendChromeInstallSubDirectory(result, true /* include_suffix */);
+  result->push_back(L'\\');
   result->append(kUserDataDirname);
   return true;
 }
 
 bool GetDefaultCrashDumpLocation(std::wstring* crash_dir) {
   // In order to be able to start crash handling very early, we do not rely on
   // chrome's PathService entries (for DIR_CRASH_DUMPS) being available on
   // Windows. See https://crbug.com/564398.
   if (!GetDefaultUserDataDirectory(crash_dir))
     return false;
 
   // We have to make sure the user data dir exists on first run. See
   // http://crbug.com/591504.
-  if (!RecursiveDirectoryCreate(crash_dir->c_str()))
+  if (!RecursiveDirectoryCreate(*crash_dir))
     return false;
   crash_dir->append(L"\\Crashpad");
   return true;
 }
 
 std::string GetEnvironmentString(const std::string& variable_name) {
-  return UTF16ToUTF8(GetEnvironmentString16(UTF8ToUTF16(variable_name)));
+  return UTF16ToUTF8(
+      GetEnvironmentString16(UTF8ToUTF16(variable_name).c_str()));
 }
 
-std::wstring GetEnvironmentString16(const std::wstring& variable_name) {
-  DWORD value_length =
-      ::GetEnvironmentVariable(variable_name.c_str(), nullptr, 0);
-  if (value_length == 0)
+std::wstring GetEnvironmentString16(const wchar_t* variable_name) {
+  DWORD value_length = ::GetEnvironmentVariableW(variable_name, nullptr, 0);
+  if (!value_length)
     return std::wstring();
-  std::unique_ptr<wchar_t[]> value(new wchar_t[value_length]);
-  ::GetEnvironmentVariable(variable_name.c_str(), value.get(), value_length);
-  return value.get();
+  std::wstring value(value_length, L'\0');
+  value_length =
+      ::GetEnvironmentVariableW(variable_name, &value[0], value_length);
+  if (!value_length || value_length >= value.size())
+    return std::wstring();
+  value.resize(value_length);
+  return value;
 }
 
 bool SetEnvironmentString(const std::string& variable_name,
                           const std::string& new_value) {
   return SetEnvironmentString16(UTF8ToUTF16(variable_name),
                                 UTF8ToUTF16(new_value));
 }
 
 bool SetEnvironmentString16(const std::wstring& variable_name,
                             const std::wstring& new_value) {
   return !!SetEnvironmentVariable(variable_name.c_str(), new_value.c_str());
 }
 
 bool HasEnvironmentVariable(const std::string& variable_name) {
   return HasEnvironmentVariable16(UTF8ToUTF16(variable_name));
 }
 
 bool HasEnvironmentVariable16(const std::wstring& variable_name) {
   return !!::GetEnvironmentVariable(variable_name.c_str(), nullptr, 0);
 }
 
-bool GetExecutableVersionDetails(const std::wstring& exe_path,
+void GetExecutableVersionDetails(const std::wstring& exe_path,
                                  std::wstring* product_name,
                                  std::wstring* version,
                                  std::wstring* special_build,
                                  std::wstring* channel_name) {
   assert(product_name);
   assert(version);
   assert(special_build);
   assert(channel_name);
 
   // Default values in case we don't find a version resource.
   *product_name = L"Chrome";
   *version = L"0.0.0.0-devel";
-  *channel_name = kChromeChannelUnknown;
   special_build->clear();
 
   DWORD dummy = 0;
   DWORD length = ::GetFileVersionInfoSize(exe_path.c_str(), &dummy);
   if (length) {
     std::unique_ptr<char> data(new char[length]);
     if (::GetFileVersionInfo(exe_path.c_str(), dummy, length, data.get())) {
       GetValueFromVersionResource(data.get(), L"ProductVersion", version);
 
       std::wstring official_build;
       GetValueFromVersionResource(data.get(), L"Official Build",
                                   &official_build);
       if (official_build != L"1")
         version->append(L"-devel");
       GetValueFromVersionResource(data.get(), L"ProductShortName",
                                   product_name);
       GetValueFromVersionResource(data.get(), L"SpecialBuild", special_build);
     }
   }
-  GetChromeChannelName(!IsSystemInstall(exe_path.c_str()), true, channel_name);
-  return true;
+  *channel_name = GetChromeChannelName(true /* add_modifier */);
 }
 
-void GetChromeChannelName(bool is_per_user_install,
-                          bool add_modifier,
-                          std::wstring* channel_name) {
-  // See GoogleChromeSxSDistribution::GetChromeChannel.
-  if (IsSxSChrome(GetCurrentProcessExePath().c_str())) {
-    channel_name->assign(kChromeChannelCanary);
-    return;
-  }
-
-  // InitChannelInfo in google_update_settings.cc only reports a failure in the
-  // case of multi-install Chrome where the binaries' ClientState key exists,
-  // but that the "ap" value therein cannot be read due to some reason *other*
-  // than it not being present. This should be exceedingly rare. For
-  // simplicity's sake, use an empty |value| in case of any error whatsoever
-  // here.
-  std::wstring value;
-  bool is_multi_install = IsMultiInstall(!is_per_user_install);
-  if (is_multi_install) {
-    std::wstring full_key_path(kRegPathClientState);
-    full_key_path.append(1, L'\\');
-    full_key_path.append(kAppGuidGoogleBinaries);
-    nt::QueryRegValueSZ(is_per_user_install ? nt::HKCU : nt::HKLM, nt::WOW6432,
-                        full_key_path.c_str(), kRegApField, &value);
-  } else {
-    std::wstring full_key_path(kRegPathClientState);
-    full_key_path.append(1, L'\\');
-    full_key_path.append(kAppGuidGoogleChrome);
-    nt::QueryRegValueSZ(is_per_user_install ? nt::HKCU : nt::HKLM, nt::WOW6432,
-                        full_key_path.c_str(), kRegApField, &value);
-  }
-
-  static constexpr wchar_t kChromeChannelBetaPattern[] = L"1?1-*";
-  static constexpr wchar_t kChromeChannelBetaX64Pattern[] = L"*x64-beta*";
-  static constexpr wchar_t kChromeChannelDevPattern[] = L"2?0-d*";
-  static constexpr wchar_t kChromeChannelDevX64Pattern[] = L"*x64-dev*";
-
-  std::transform(value.begin(), value.end(), value.begin(), ::tolower);
-
-  // Empty channel names or those containing "stable" should be reported as
-  // an empty string (with the optional modifier).
-  if (value.empty() ||
-      (value.find(kChromeChannelStableExplicit) != std::wstring::npos)) {
-    channel_name->clear();
-  } else if (MatchPattern(value, kChromeChannelDevPattern) ||
-             MatchPattern(value, kChromeChannelDevX64Pattern)) {
-    channel_name->assign(kChromeChannelDev);
-  } else if (MatchPattern(value, kChromeChannelBetaPattern) ||
-             MatchPattern(value, kChromeChannelBetaX64Pattern)) {
-    channel_name->assign(kChromeChannelBeta);
-  } else {
-    // Report values with garbage as stable since they will match the stable
-    // rules in the update configs. ChannelInfo::GetChannelName painstakingly
-    // strips off known modifiers (e.g., "-multi-full") to see if the empty
-    // string remains, returning channel "unknown" if not. This differs here in
-    // that some clients will tag crashes as "stable" rather than "unknown" via
-    // this codepath, but it is an accurate reflection of which update channel
-    // the client is on according to the server-side rules.
-    channel_name->clear();
-  }
-
-  // Tag the channel name if this is a multi-install.
-  if (add_modifier && is_multi_install) {
-    if (!channel_name->empty())
-      channel_name->push_back(L'-');
-    channel_name->push_back(L'm');
-  }
-}
-
-std::string GetGoogleUpdateVersion() {
-  // TODO(ananta)
-  // Consider whether Chromium should connect to Google update to manage
-  // updates. Should this be returning an empty string for Chromium builds?.
-  std::wstring update_version;
-  if (nt::QueryRegValueSZ(nt::AUTO, nt::WOW6432, kRegPathGoogleUpdate,
-                          kRegGoogleUpdateVersion, &update_version))
-    return UTF16ToUTF8(update_version);
-
-  return std::string();
-}
-
-std::wstring GetChromeInstallSubDirectory() {
-#if defined(GOOGLE_CHROME_BUILD)
-  std::wstring result = kGoogleChromeInstallSubDir1;
-  result += L"\\";
-  result += kGoogleChromeInstallSubDir2;
-  if (IsSxSChrome(GetCurrentProcessExePath().c_str()))
-    result += kSxSSuffix;
-  return result;
-#else
-  return std::wstring(kChromiumInstallSubDir);
-#endif
+std::wstring GetChromeChannelName(bool add_modifier) {
+  const std::wstring& channel = InstallDetails::Get().channel();
+  if (!add_modifier || !IsMultiInstall())
+    return channel;
+  if (channel.empty())
+    return L"m";
+  return channel + L"-m";
 }
 
 std::wstring GetBrowserCrashDumpAttemptsRegistryPath() {
-  std::wstring registry_path = GetChromeInstallRegistryPath();
-  registry_path += kBrowserCrashDumpMetricsSubKey;
-  return registry_path;
+  return GetChromeInstallRegistryPath().append(kBrowserCrashDumpMetricsSubKey);
 }
 
 bool MatchPattern(const std::wstring& source, const std::wstring& pattern) {
   assert(pattern.find(L"**") == std::wstring::npos);
   return MatchPatternImpl(source, pattern, 0, 0);
 }
 
 std::string UTF16ToUTF8(const std::wstring& source) {
   if (source.empty() ||
       static_cast<int>(source.size()) > std::numeric_limits<int>::max()) {
@@ skipping 34 matching lines @@
                                         bool trim_spaces) {
   return TokenizeStringT<std::string>(str, delimiter, trim_spaces);
 }
 
 std::vector<std::wstring> TokenizeString16(const std::wstring& str,
                                            wchar_t delimiter,
                                            bool trim_spaces) {
   return TokenizeStringT<std::wstring>(str, delimiter, trim_spaces);
 }
 
-bool CompareVersionStrings(const std::string& version1,
-                           const std::string& version2,
-                           int* result) {
-  if (version1.empty() || version2.empty())
-    return false;
-
-  // Tokenize both version strings with "." as the separator. If either of
-  // the returned token lists are empty then bail.
-  std::vector<std::string> version1_components =
-      TokenizeString(version1, '.', false);
-  if (version1_components.empty())
-    return false;
-
-  std::vector<std::string> version2_components =
-      TokenizeString(version2, '.', false);
-  if (version2_components.empty())
-    return false;
-
-  // You may have less tokens in either string. Use the minimum of the number
-  // of tokens as the initial count.
-  const size_t count =
-      std::min(version1_components.size(), version2_components.size());
-  for (size_t i = 0; i < count; ++i) {
-    // If either of the version components don't contain valid numeric digits
-    // bail.
-    if (!IsValidNumber(version1_components[i]) ||
-        !IsValidNumber(version2_components[i])) {
-      return false;
-    }
-
-    int version1_component = std::stoi(version1_components[i]);
-    int version2_component = std::stoi(version2_components[i]);
-
-    if (version1_component > version2_component) {
-      *result = 1;
-      return true;
-    }
-
-    if (version1_component < version2_component) {
-      *result = -1;
-      return true;
-    }
-  }
-
-  // Handle remaining tokens. Here if we have non zero tokens remaining in the
-  // version 1 list then it means that the version1 string is larger. If the
-  // version 1 token list has tokens left, then if either of these tokens is
-  // greater than 0 then it means that the version1 string is smaller than the
-  // version2 string.
-  if (version1_components.size() > version2_components.size()) {
-    for (size_t i = count; i < version1_components.size(); ++i) {
-      // If the version components don't contain valid numeric digits bail.
-      if (!IsValidNumber(version1_components[i]))
-        return false;
-
-      if (std::stoi(version1_components[i]) > 0) {
-        *result = 1;
-        return true;
-      }
-    }
-  } else if (version1_components.size() < version2_components.size()) {
-    for (size_t i = count; i < version2_components.size(); ++i) {
-      // If the version components don't contain valid numeric digits bail.
-      if (!IsValidNumber(version2_components[i]))
-        return false;
-
-      if (std::stoi(version2_components[i]) > 0) {
-        *result = -1;
-        return true;
-      }
-    }
-  }
-  // Here it means that both versions are equal.
-  *result = 0;
-  return true;
-}
-
 std::string GetSwitchValueFromCommandLine(const std::string& command_line,
                                           const std::string& switch_name) {
   assert(!command_line.empty());
   assert(!switch_name.empty());
 
   std::string command_line_copy = command_line;
   // Remove leading and trailing spaces.
   TrimT<std::string>(&command_line_copy);
 
   // Find the switch in the command line. If we don't find the switch, return
@@ skipping 22 matching lines @@
   if (switch_value_end_offset == std::string::npos)
     switch_value_end_offset = command_line_copy.length();
 
   std::string switch_value = command_line_copy.substr(
       switch_value_start_offset,
       switch_value_end_offset - (switch_offset + switch_token.length()));
   TrimT<std::string>(&switch_value);
   return switch_value;
 }
 
+// This function takes these inputs rather than accessing the module's
+// InstallDetails instance since it is used to bootstrap InstallDetails.
+std::wstring DetermineChannel(const InstallConstants& mode,
+                              bool system_level,
+                              bool multi_install) {
+  if (!kUseGoogleUpdateIntegration)
+    return std::wstring(kChromeChannelUnknown);
+
+  switch (mode.channel_strategy) {
+    case ChannelStrategy::UNSUPPORTED:
+      assert(false);
+      break;
+    case ChannelStrategy::ADDITIONAL_PARAMETERS:
+      return ChannelFromAdditionalParameters(mode, system_level, multi_install);
+    case ChannelStrategy::FIXED:
+      return mode.default_channel_name;
+  }
+
+  return std::wstring();
+}
+
 }  // namespace install_static