Use a valid /prefetch argument when launching a process.

The /prefetch:# argument that is currently added to the command line of
processes launched with content::StartSandboxedProcess is ignored by
Windows because # doesn't respect the [1, 8] constraint.

This CL ensures that a valid /prefetch:# argument is used for every
process launch (except when the feature is disabled by the PreRead
field trial).

BUG=577698

Review URL: https://codereview.chromium.org/1612663002

Cr-Commit-Position: refs/heads/master@{#373241}
(cherry picked from commit 343068c41c299e65a87d935654f0b81a9935250f)

Conflicts:
	chrome/service/DEPS

TBR=gab@chromium.org

Review URL: https://codereview.chromium.org/1727983002 .

Cr-Commit-Position: refs/branch-heads/2623@{#484}
Cr-Branched-From: 92d77538a86529ca35f9220bd3cd512cbea1f086-refs/heads/master@{#369907}

44 files changed, 298 insertions, 47 deletions

diff --git a/chrome/app/chrome_exe_main_win.cc b/chrome/app/chrome_exe_main_win.cc
index 2102ae1..089ca12 100644
--- a/chrome/app/chrome_exe_main_win.cc
+++ b/chrome/app/chrome_exe_main_win.cc
@@ -17,6 +17,8 @@
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/strings/string16.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "base/win/windows_version.h"
@@ -26,10 +28,12 @@
 #include "chrome/browser/policy/policy_path_parser.h"
 #include "chrome/common/chrome_paths_internal.h"
 #include "chrome/common/chrome_switches.h"
+#include "chrome/installer/util/browser_distribution.h"
 #include "chrome_elf/chrome_elf_main.h"
 #include "components/crash/content/app/crash_reporter_client.h"
 #include "components/crash/content/app/crashpad.h"
 #include "components/startup_metric_utils/browser/startup_metric_utils.h"
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/result_codes.h"
 #include "third_party/crashpad/crashpad/handler/handler_main.h"
@@ -152,15 +156,39 @@ int RunAsCrashpadHandler(const base::CommandLine& command_line) {
   scoped_ptr<char* []> argv_as_utf8(new char*[argv.size() + 1]);
   std::vector<std::string> storage;
   storage.reserve(argv.size());
+
+  size_t arg_append_index = 0;
   for (size_t i = 0; i < argv.size(); ++i) {
+    // Remove arguments starting with '/' as they are not supported by crashpad.
+    if (!argv[i].empty() && argv[i].front() == L'/')
+      continue;
+
     storage.push_back(base::UTF16ToUTF8(argv[i]));
-    argv_as_utf8[i] = &storage[i][0];
+    argv_as_utf8[arg_append_index] = &storage[arg_append_index][0];
+    ++arg_append_index;
   }
-  argv_as_utf8[argv.size()] = nullptr;
-  return crashpad::HandlerMain(static_cast<int>(argv.size()),
+  argv_as_utf8[arg_append_index] = nullptr;
+
+  return crashpad::HandlerMain(static_cast<int>(storage.size()),
                                argv_as_utf8.get());
 }
 
+// Returns true if |command_line| contains a /prefetch:# argument where # is in
+// [1, 8].
+bool HasValidWindowsPrefetchArgument(const base::CommandLine& command_line) {
+  const base::char16 kPrefetchArgumentPrefix[] = L"/prefetch:";
+
+  for (const auto& arg : command_line.argv()) {
+    if (arg.size() == arraysize(kPrefetchArgumentPrefix) &&
+        base::StartsWith(arg, kPrefetchArgumentPrefix,
+                         base::CompareCase::SENSITIVE)) {
+      return arg[arraysize(kPrefetchArgumentPrefix) - 1] >= L'1' &&
+             arg[arraysize(kPrefetchArgumentPrefix) - 1] <= L'8';
+    }
+  }
+  return false;
+}
+
 }  // namespace
 
 // This helper is looked up in the browser to retrieve the crash reports. See
@@ -183,10 +211,22 @@ int main() {
 #endif
   // Initialize the CommandLine singleton from the environment.
   base::CommandLine::Init(0, nullptr);
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+
+  const std::string process_type =
+      command_line->GetSwitchValueASCII(switches::kProcessType);
+
+  startup_metric_utils::InitializePreReadOptions(
+      BrowserDistribution::GetDistribution()->GetRegistryPath());
 
-  std::string process_type =
-      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
-          switches::kProcessType);
+  // Confirm that an explicit prefetch profile is used for all process types
+  // except for the browser process. Any new process type will have to assign
+  // itself a prefetch id. See kPrefetchArgument* constants in
+  // content_switches.cc for details.
+  DCHECK(!startup_metric_utils::GetPreReadOptions().use_prefetch_argument ||
+         process_type.empty() ||
+         HasValidWindowsPrefetchArgument(*command_line));
 
   if (process_type == switches::kCrashpadHandler)
     return RunAsCrashpadHandler(*base::CommandLine::ForCurrentProcess());
@@ -210,7 +250,7 @@ int main() {
   if (base::win::GetVersion() >= base::win::VERSION_WIN7)
     EnableHighDPISupport();
 
-  if (AttemptFastNotify(*base::CommandLine::ForCurrentProcess()))
+  if (AttemptFastNotify(*command_line))
     return 0;
 
   // Load and launch the chrome dll. *Everything* happens inside.
diff --git a/chrome/app/chrome_watcher_command_line_win.cc b/chrome/app/chrome_watcher_command_line_win.cc
index 9c8106b..2f79dbc 100644
--- a/chrome/app/chrome_watcher_command_line_win.cc
+++ b/chrome/app/chrome_watcher_command_line_win.cc
@@ -15,6 +15,7 @@
 #include "base/strings/stringprintf.h"
 #include "base/win/win_util.h"
 #include "chrome/common/chrome_switches.h"
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 #include "content/public/common/content_switches.h"
 
 namespace {
@@ -154,6 +155,12 @@ base::CommandLine GenerateChromeWatcherCommandLine(
   AppendHandleSwitch(kOnIninitializedEventHandleSwitch, on_initialized_event,
                      &command_line);
   AppendHandleSwitch(kParentHandleSwitch, parent_process, &command_line);
+
+#if defined(OS_WIN)
+  if (startup_metric_utils::GetPreReadOptions().use_prefetch_argument)
+    command_line.AppendArg(switches::kPrefetchArgumentWatcher);
+#endif  // defined(OS_WIN)
+
   return command_line;
 }
 
diff --git a/chrome/app/main_dll_loader_win.cc b/chrome/app/main_dll_loader_win.cc
index f28d301..1c24da1 100644
--- a/chrome/app/main_dll_loader_win.cc
+++ b/chrome/app/main_dll_loader_win.cc
@@ -39,7 +39,6 @@
 #include "chrome/common/chrome_result_codes.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/env_vars.h"
-#include "chrome/installer/util/browser_distribution.h"
 #include "chrome/installer/util/google_update_constants.h"
 #include "chrome/installer/util/google_update_settings.h"
 #include "chrome/installer/util/install_util.h"
@@ -64,13 +63,11 @@ HMODULE LoadModuleWithDirectory(const base::FilePath& module) {
   ::SetCurrentDirectoryW(module.DirName().value().c_str());
 
   // Get pre-read options from the PreRead field trial.
-  startup_metric_utils::InitializePreReadOptions(
-      BrowserDistribution::GetDistribution()->GetRegistryPath());
   const startup_metric_utils::PreReadOptions pre_read_options =
       startup_metric_utils::GetPreReadOptions();
 
   // Pre-read the binary to warm the memory caches (avoids a lot of random IO).
-  if (!pre_read_options.no_pre_read) {
+  if (pre_read_options.pre_read) {
     base::ThreadPriority previous_priority = base::ThreadPriority::NORMAL;
     if (pre_read_options.high_priority) {
       previous_priority = base::PlatformThread::GetCurrentThreadPriority();
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 3b535ce..a66cec3 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -163,6 +163,10 @@ source_set("browser") {
     "//components/ssl_errors",
     "//components/startup_metric_utils/browser:lib",
     "//components/startup_metric_utils/browser:message_filter_lib",
+
+    # TODO(fdoray): Remove this once the PreRead field trial has expired.
+    # crbug.com/577698
+    "//components/startup_metric_utils/common",
     "//components/strings",
     "//components/suggestions",
     "//components/sync_bookmarks",
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index 4dff7d2..2a2c668 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -111,6 +111,7 @@
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 #include "ui/views/focus/view_storage.h"
 #elif defined(OS_MACOSX)
 #include "chrome/browser/chrome_browser_main_mac.h"
@@ -1268,6 +1269,11 @@ void BrowserProcessImpl::RestartBackgroundInstance() {
       new_cl->AppendSwitch(kSwitchesToAddOnAutorestart[i]);
   }
 
+#if defined(OS_WIN)
+  if (startup_metric_utils::GetPreReadOptions().use_prefetch_argument)
+    new_cl->AppendArg(switches::kPrefetchArgumentBrowserBackground);
+#endif  // defined(OS_WIN)
+
   DLOG(WARNING) << "Shutting down current instance of the browser.";
   chrome::AttemptExit();
 
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 75aefe8..512df64 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -583,7 +583,10 @@ void SetupPreReadFieldTrial() {
       registry_path,
       base::Bind(&ChromeMetricsServiceAccessor::RegisterSyntheticFieldTrial));
 
-  // After startup is complete, update the pre-read group in the registry. The
+  // Initialize the PreRead options for the current process.
+  startup_metric_utils::InitializePreReadOptions(registry_path);
+
+  // After startup is complete, update the PreRead group in the registry. The
   // group written in the registry will be used for the next startup.
   BrowserThread::PostAfterStartupTask(
       FROM_HERE, content::BrowserThread::GetBlockingPool(),
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index c3bf71a..21f7f95 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -168,6 +168,7 @@
 #include "base/strings/string_tokenizer.h"
 #include "base/win/windows_version.h"
 #include "chrome/browser/chrome_browser_main_win.h"
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 #include "sandbox/win/src/sandbox_policy.h"
 #elif defined(OS_MACOSX)
 #include "chrome/browser/chrome_browser_main_mac.h"
@@ -2690,6 +2691,10 @@ bool ChromeContentBrowserClient::IsWin32kLockdownEnabledForMimeType(
 
   return false;
 }
+
+bool ChromeContentBrowserClient::ShouldUseWindowsPrefetchArgument() const {
+  return startup_metric_utils::GetPreReadOptions().use_prefetch_argument;
+}
 #endif  // defined(OS_WIN)
 
 void ChromeContentBrowserClient::RegisterFrameMojoShellServices(
diff --git a/chrome/browser/chrome_content_browser_client.h b/chrome/browser/chrome_content_browser_client.h
index 6d88e71..060501a 100644
--- a/chrome/browser/chrome_content_browser_client.h
+++ b/chrome/browser/chrome_content_browser_client.h
@@ -281,6 +281,7 @@ class ChromeContentBrowserClient : public content::ContentBrowserClient {
       int sandbox_type) const override;
   bool IsWin32kLockdownEnabledForMimeType(
       const std::string& mime_type) const override;
+  bool ShouldUseWindowsPrefetchArgument() const override;
 #endif
   void RegisterFrameMojoShellServices(
       content::ServiceRegistry* registry,
diff --git a/chrome/chrome.gyp b/chrome/chrome.gyp
index 5a16c54..1f5fd54 100644
--- a/chrome/chrome.gyp
+++ b/chrome/chrome.gyp
@@ -753,8 +753,6 @@
             'service/service_process.h',
             'service/service_process_prefs.cc',
             'service/service_process_prefs.h',
-            'service/service_utility_process_host.cc',
-            'service/service_utility_process_host.h',
           ],
           'include_dirs': [
             '..',
@@ -773,11 +771,16 @@
                 'service/cloud_print/print_system_dummy.cc',
               ],
             }],
-            ['OS!="win"', {
-              'sources!': [
+            ['OS=="win"', {
+              'sources': [
                 'service/service_utility_process_host.cc',
                 'service/service_utility_process_host.h',
               ],
+              'deps': [
+                # TODO(fdoray): Remove this once the PreRead field trial has
+                # expired. crbug.com/577698
+                '../components/components.gyp:startup_metric_utils_common',
+              ],
             }],
           ],
         },
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index d21934f..1e31929 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -3179,6 +3179,9 @@
         '../components/components.gyp:signin_core_browser',
         '../components/components.gyp:startup_metric_utils_browser',
         '../components/components.gyp:startup_metric_utils_browser_message_filter',
+        # TODO(fdoray): Remove this once the PreRead field trial has expired.
+        # crbug.com/577698
+        '../components/components.gyp:startup_metric_utils_common',
         '../components/components.gyp:sync_bookmarks',
         '../components/components.gyp:sync_driver',
         '../components/components.gyp:sync_sessions',
diff --git a/chrome/chrome_common.gypi b/chrome/chrome_common.gypi
index bb4e2c3..87b7387 100644
--- a/chrome/chrome_common.gypi
+++ b/chrome/chrome_common.gypi
@@ -340,6 +340,9 @@
         '<(DEPTH)/components/components.gyp:metrics_net',
         '<(DEPTH)/components/components.gyp:omnibox_common',
         '<(DEPTH)/components/components.gyp:policy_component_common',
+        # TODO(fdoray): Remove this once the PreRead field trial has expired.
+        # crbug.com/577698
+        '<(DEPTH)/components/components.gyp:startup_metric_utils_common',
         '<(DEPTH)/components/components.gyp:translate_core_common',
         '<(DEPTH)/components/components.gyp:variations',
         '<(DEPTH)/components/components.gyp:version_info',
diff --git a/chrome/chrome_installer_util.gypi b/chrome/chrome_installer_util.gypi
index 757f4d8..e21ccbd 100644
--- a/chrome/chrome_installer_util.gypi
+++ b/chrome/chrome_installer_util.gypi
@@ -122,6 +122,9 @@
             '<(DEPTH)/chrome/chrome_resources.gyp:chrome_strings',
             '<(DEPTH)/chrome/common_constants.gyp:common_constants',
             '<(DEPTH)/components/components.gyp:metrics',
+            # TODO(fdoray): Remove this once the PreRead field trial has
+            # expired. crbug.com/577698
+            '<(DEPTH)/components/components.gyp:startup_metric_utils_common',
             '<(DEPTH)/components/components.gyp:variations',
             '<(DEPTH)/courgette/courgette.gyp:courgette_lib',
             '<(DEPTH)/crypto/crypto.gyp:crypto',
diff --git a/chrome/common/BUILD.gn b/chrome/common/BUILD.gn
index fb57a95..015ede6 100644
--- a/chrome/common/BUILD.gn
+++ b/chrome/common/BUILD.gn
@@ -211,6 +211,14 @@ static_library("common") {
       sources += rebase_path(gypi_values.chrome_common_service_process_sources,
                              ".",
                              "//chrome")
+
+      if (is_win) {
+        deps = [
+          # TODO(fdoray): Remove this once the PreRead field trial has expired.
+          # crbug.com/577698
+          "//components/startup_metric_utils/common",
+        ]
+      }
     }
   }
 
diff --git a/chrome/common/DEPS b/chrome/common/DEPS
index ead1d81..52cf585 100644
--- a/chrome/common/DEPS
+++ b/chrome/common/DEPS
@@ -21,6 +21,9 @@ include_rules = [
   "+components/printing/common",
   "+components/policy/core/common",
   "+components/signin/core/common",
+  # TODO(fdoray): Remove this once the PreRead field trial has expired.
+  # crbug.com/577698
+  "+components/startup_metric_utils/common",
   "+components/strings/grit",
   "+components/translate/core/common",
   "+components/url_formatter",
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 1b9d664..c154752 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1254,6 +1254,14 @@ const char kForceImmersive[]                = "force-immersive";
 // This flag is only relevant for Windows currently.
 const char kNoNetworkProfileWarning[]       = "no-network-profile-warning";
 
+// /prefetch:# arguments for the browser process launched in background mode and
+// for the watcher process. Use profiles 5, 6 and 7 as documented on
+// kPrefetchArgument* in content_switches.cc.
+const char kPrefetchArgumentBrowserBackground[] = "/prefetch:5";
+const char kPrefetchArgumentWatcher[] = "/prefetch:6";
+// /prefetch:7 is used by crashpad, which can't depend on constants defined
+// here. See crashpad_win.cc for more details.
+
 // For the DelegateExecute verb handler to launch Chrome in desktop mode on
 // Windows 8 and higher.  Used when relaunching metro Chrome.
 const char kForceDesktop[]                  = "force-desktop";
diff --git a/chrome/common/chrome_switches.h b/chrome/common/chrome_switches.h
index 71aac50..4194ae0 100644
--- a/chrome/common/chrome_switches.h
+++ b/chrome/common/chrome_switches.h
@@ -360,6 +360,8 @@ extern const char kForceDesktop[];
 extern const char kForceImmersive[];
 extern const char kHideIcons[];
 extern const char kNoNetworkProfileWarning[];
+extern const char kPrefetchArgumentBrowserBackground[];
+extern const char kPrefetchArgumentWatcher[];
 extern const char kRelaunchShortcut[];
 extern const char kShowIcons[];
 extern const char kUninstall[];
diff --git a/chrome/common/service_process_util.cc b/chrome/common/service_process_util.cc
index 336c011..cd0724b 100644
--- a/chrome/common/service_process_util.cc
+++ b/chrome/common/service_process_util.cc
@@ -31,6 +31,10 @@
 #include "google_apis/gaia/gaia_switches.h"
 #include "ui/base/ui_base_switches.h"
 
+#if defined(OS_WIN)
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
+#endif  // defined(OS_WIN)
+
 #if !defined(OS_MACOSX)
 
 namespace {
@@ -160,6 +164,12 @@ scoped_ptr<base::CommandLine> CreateServiceProcessCommandLine() {
   scoped_ptr<base::CommandLine> command_line(new base::CommandLine(exe_path));
   command_line->AppendSwitchASCII(switches::kProcessType,
                                   switches::kServiceProcess);
+
+#if defined(OS_WIN)
+  if (startup_metric_utils::GetPreReadOptions().use_prefetch_argument)
+    command_line->AppendArg(switches::kPrefetchArgumentOther);
+#endif  // defined(OS_WIN)
+
   static const char* const kSwitchesToCopy[] = {
     switches::kCloudPrintSetupProxy,
     switches::kCloudPrintURL,
diff --git a/chrome/installer/util/BUILD.gn b/chrome/installer/util/BUILD.gn
index 0faa59e..45a8579 100644
--- a/chrome/installer/util/BUILD.gn
+++ b/chrome/installer/util/BUILD.gn
@@ -109,6 +109,10 @@ static_library("with_no_strings") {
       ":generate_strings",
       "//base/third_party/dynamic_annotations",
       "//components/metrics",
+
+      # TODO(fdoray): Remove this once the PreRead field trial has expired.
+      # crbug.com/577698
+      "//components/startup_metric_utils/common",
       "//courgette:courgette_lib",
       "//crypto",
       "//third_party/bspatch",
diff --git a/chrome/installer/util/DEPS b/chrome/installer/util/DEPS
index 448e750..2e7e849 100644
--- a/chrome/installer/util/DEPS
+++ b/chrome/installer/util/DEPS
@@ -4,5 +4,10 @@ include_rules = [
   "+chrome/grit/chromium_strings.h",
 
   "+components/metrics",
+
+  # TODO(fdoray): Remove this once the PreRead field trial has expired.
+  # crbug.com/577698
+  "+components/startup_metric_utils/common",
+
   "+third_party/crashpad",
 ]
diff --git a/chrome/installer/util/auto_launch_util.cc b/chrome/installer/util/auto_launch_util.cc
index e61cf76..9fbeab7 100644
--- a/chrome/installer/util/auto_launch_util.cc
+++ b/chrome/installer/util/auto_launch_util.cc
@@ -21,6 +21,7 @@
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/installer/util/util_constants.h"
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 #include "crypto/sha2.h"
 
 namespace {
@@ -59,6 +60,9 @@ void EnableBackgroundStartAtLogin() {
   base::CommandLine cmd_line(application_dir.Append(installer::kChromeExe));
   cmd_line.AppendSwitch(switches::kNoStartupWindow);
 
+  if (startup_metric_utils::GetPreReadOptions().use_prefetch_argument)
+    cmd_line.AppendArg(switches::kPrefetchArgumentBrowserBackground);
+
   base::win::AddCommandToAutoRun(HKEY_CURRENT_USER, GetAutoLaunchKeyName(),
                                  cmd_line.GetCommandLineString());
 }
diff --git a/chrome/service/BUILD.gn b/chrome/service/BUILD.gn
index bb741209..a1ef809 100644
--- a/chrome/service/BUILD.gn
+++ b/chrome/service/BUILD.gn
@@ -71,6 +71,11 @@ static_library("service") {
       "service_utility_process_host.cc",
       "service_utility_process_host.h",
     ]
+    deps += [
+      # TODO(fdoray): Remove this once the PreRead field trial has expired.
+      # crbug.com/577698
+      "//components/startup_metric_utils/common",
+    ]
   } else {
     sources += [ "cloud_print/print_system_dummy.cc" ]
   }
diff --git a/chrome/service/DEPS b/chrome/service/DEPS
index 989d2ce..54a3081 100644
--- a/chrome/service/DEPS
+++ b/chrome/service/DEPS
@@ -1,5 +1,10 @@
 include_rules = [
   "+chrome/grit",  # For generated headers.
+
+  # TODO(fdoray): Remove this once the PreRead field trial has expired.
+  # crbug.com/577698
+  "+components/startup_metric_utils/common",
+
   "+components/version_info",
   "+sandbox/win/src",
 ]
diff --git a/chrome/service/service_utility_process_host.cc b/chrome/service/service_utility_process_host.cc
index 3ed91b4..3dad747 100644
--- a/chrome/service/service_utility_process_host.cc
+++ b/chrome/service/service_utility_process_host.cc
@@ -34,6 +34,10 @@
 #include "sandbox/win/src/sandbox_types.h"
 #include "ui/base/ui_base_switches.h"
 
+#if defined(OS_WIN)
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
+#endif  // defined(OS_WIN)
+
 namespace {
 
 using content::ChildProcessHost;
@@ -225,6 +229,11 @@ bool ServiceUtilityProcessHost::StartProcess(bool no_sandbox) {
   cmd_line.AppendSwitchASCII(switches::kProcessChannelID, channel_id);
   cmd_line.AppendSwitch(switches::kLang);
 
+#if defined(OS_WIN)
+  if (startup_metric_utils::GetPreReadOptions().use_prefetch_argument)
+    cmd_line.AppendArg(switches::kPrefetchArgumentOther);
+#endif  // defined(OS_WIN)
+
   if (Launch(&cmd_line, no_sandbox)) {
     ReportUmaEvent(SERVICE_UTILITY_STARTED);
     return true;
diff --git a/cloud_print/service/win/chrome_launcher.cc b/cloud_print/service/win/chrome_launcher.cc
index 5c9013a..d386342 100644
--- a/cloud_print/service/win/chrome_launcher.cc
+++ b/cloud_print/service/win/chrome_launcher.cc
@@ -214,6 +214,10 @@ void ChromeLauncher::Run() {
       cmd.AppendSwitchPath(switches::kUserDataDir, user_data_);
       cmd.AppendSwitch(switches::kNoServiceAutorun);
 
+#if defined(OS_WIN)
+      cmd.AppendArg(switches::kPrefetchArgumentOther);
+#endif  // defined(OS_WIN)
+
       // Optional.
       cmd.AppendSwitch(switches::kDisableDefaultApps);
       cmd.AppendSwitch(switches::kDisableExtensions);
diff --git a/components/crash.gypi b/components/crash.gypi
index 00ee69c..8ef86ad 100644
--- a/components/crash.gypi
+++ b/components/crash.gypi
@@ -217,6 +217,13 @@
           ],
           'defines': ['CRASH_IMPLEMENTATION'],
           'conditions': [
+            ['OS=="win"', {
+              'dependencies': [
+                # TODO(fdoray): Remove this once the PreRead field trial has
+                # expired. crbug.com/577698
+                '<(DEPTH)/components/components.gyp:startup_metric_utils_common',
+              ],
+            }],
             ['OS=="mac" or OS=="win"', {
               'dependencies': [
                 '../third_party/crashpad/crashpad/client/client.gyp:crashpad_client',
diff --git a/components/crash/content/app/BUILD.gn b/components/crash/content/app/BUILD.gn
index 52140ce..3def677 100644
--- a/components/crash/content/app/BUILD.gn
+++ b/components/crash/content/app/BUILD.gn
@@ -49,6 +49,13 @@ source_set("app") {
   ]
 
   deps += [ ":lib" ]
+  if (is_win) {
+    deps += [
+      # TODO(fdoray): Remove this once the PreRead field trial has expired.
+      # crbug.com/577698
+      "//components/startup_metric_utils/common",
+    ]
+  }
   if (is_mac || is_win) {
     deps += [ "//third_party/crashpad/crashpad/client" ]
   }
diff --git a/components/crash/content/app/DEPS b/components/crash/content/app/DEPS
index 80bc21a..01c710b 100644
--- a/components/crash/content/app/DEPS
+++ b/components/crash/content/app/DEPS
@@ -3,6 +3,11 @@ include_rules = [
 
   "+content/public/common/content_descriptors.h",
   "+content/public/common/result_codes.h",
+
+  # TODO(fdoray): Remove this once the PreRead field trial has expired.
+  # crbug.com/577698
+  "+components/startup_metric_utils/common/pre_read_field_trial_utils_win.h",
+
   "+third_party/crashpad",
   "+third_party/kasko",
   "+third_party/lss/linux_syscall_support.h",
diff --git a/components/crash/content/app/crashpad_win.cc b/components/crash/content/app/crashpad_win.cc
index 1c241ca..95e53e2 100644
--- a/components/crash/content/app/crashpad_win.cc
+++ b/components/crash/content/app/crashpad_win.cc
@@ -16,6 +16,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "components/crash/content/app/crash_reporter_client.h"
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 #include "third_party/crashpad/crashpad/client/crashpad_client.h"
 #include "third_party/crashpad/crashpad/client/crashpad_info.h"
 #include "third_party/crashpad/crashpad/client/simulate_crash_win.h"
@@ -75,6 +76,13 @@ base::FilePath PlatformCrashpadInitialization(bool initial_client,
       exe_file = exe_dir.Append(FILE_PATH_LITERAL("crashpad_handler.exe"));
     } else {
       arguments.push_back("--type=crashpad-handler");
+
+      if (startup_metric_utils::GetPreReadOptions().use_prefetch_argument) {
+        // The prefetch argument added here has to be documented in
+        // chrome_switches.cc, below the kPrefetchArgument* constants. A
+        // constant can't be used here because crashpad can't depend on Chrome.
+        arguments.push_back("/prefetch:7");
+      }
     }
 
     // TODO(scottmg): See https://crashpad.chromium.org/bug/23.
diff --git a/components/nacl.gyp b/components/nacl.gyp
index a9ed69c..2fd7aba 100644
--- a/components/nacl.gyp
+++ b/components/nacl.gyp
@@ -139,6 +139,13 @@
                 '../sandbox/sandbox.gyp:sandbox_services',
               ]
             }],
+            ['OS=="win"', {
+              'dependencies': [
+                # TODO(fdoray): Remove this once the PreRead field trial has
+                # expired. crbug.com/577698
+                '../components/components.gyp:startup_metric_utils_common',
+              ]
+            }],
           ],
         },
         {
diff --git a/components/nacl/browser/BUILD.gn b/components/nacl/browser/BUILD.gn
index 63c2c9d..9b247f4 100644
--- a/components/nacl/browser/BUILD.gn
+++ b/components/nacl/browser/BUILD.gn
@@ -63,6 +63,14 @@ source_set("browser") {
     data_deps += [ "//components/nacl/loader:helper_nonsfi" ]
   }
 
+  if (is_win) {
+    deps += [
+      # TODO(fdoray): Remove this once the PreRead field trial has expired.
+      # crbug.com/577698
+      "//components/startup_metric_utils/common",
+    ]
+  }
+
   if (is_win && current_cpu == "x86") {
     data_deps += [ "//components/nacl/broker:nacl64" ]
   }
diff --git a/components/nacl/browser/DEPS b/components/nacl/browser/DEPS
index efbdb131..2e1a96b 100644
--- a/components/nacl/browser/DEPS
+++ b/components/nacl/browser/DEPS
@@ -1,4 +1,7 @@
 include_rules = [
+  # TODO(fdoray): Remove this once the PreRead field trial has expired.
+  # crbug.com/577698
+  "+components/startup_metric_utils/common",
   "+components/url_formatter",
   "+content/public/browser",
   "+content/public/test",
diff --git a/components/nacl/browser/nacl_process_host.cc b/components/nacl/browser/nacl_process_host.cc
index aa4f4c5..2ade0f7 100644
--- a/components/nacl/browser/nacl_process_host.cc
+++ b/components/nacl/browser/nacl_process_host.cc
@@ -76,6 +76,7 @@
 #include "base/win/scoped_handle.h"
 #include "components/nacl/browser/nacl_broker_service_win.h"
 #include "components/nacl/common/nacl_debug_exception_handler_win.h"
+#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 #include "content/public/common/sandbox_init.h"
 #endif
 
@@ -625,7 +626,12 @@ bool NaClProcessHost::LaunchSelLdr() {
   if (NaClBrowser::GetDelegate()->DialogsAreSuppressed())
     cmd_line->AppendSwitch(switches::kNoErrorDialogs);
 
-  // On Windows we might need to start the broker process to launch a new loader
+#if defined(OS_WIN)
+  if (startup_metric_utils::GetPreReadOptions().use_prefetch_argument)
+    cmd_line->AppendArg(switches::kPrefetchArgumentOther);
+#endif  // defined(OS_WIN)
+
+// On Windows we might need to start the broker process to launch a new loader
 #if defined(OS_WIN)
   if (RunningOnWOW64()) {
     if (!NaClBrokerService::GetInstance()->LaunchLoader(
diff --git a/components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc b/components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc
index a75a81c..dbb32bf 100644
--- a/components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc
+++ b/components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc
@@ -25,12 +25,16 @@ const char kPreReadFieldTrialName[] = "PreRead";
 // annotated with the pre-read group that is actually used during this startup.
 const char kPreReadSyntheticFieldTrialName[] = "SyntheticPreRead";
 
-// Variation names for the PreRead field trial.
+// Variation names for the PreRead field trial. All variations change the
+// default behavior, i.e. the default is the inverse of the variation. Thus,
+// variations that cancel something that is done by default have a negative
+// name.
 const base::char16 kNoPreReadVariationName[] = L"NoPreRead";
 const base::char16 kHighPriorityVariationName[] = L"HighPriority";
 const base::char16 kOnlyIfColdVariationName[] = L"OnlyIfCold";
 const base::char16 kPrefetchVirtualMemoryVariationName[] =
     L"PrefetchVirtualMemory";
+const base::char16 kNoPrefetchArgumentVariationName[] = L"NoPrefetchArgument";
 
 // Registry key in which the PreRead field trial group is stored.
 const base::char16 kPreReadFieldTrialRegistryKey[] = L"\\PreReadFieldTrial";
@@ -45,6 +49,12 @@ base::string16 GetPreReadRegistryPath(
   return product_registry_path + kPreReadFieldTrialRegistryKey;
 }
 
+// Returns true if |key| has a value named |name| which is not zero.
+bool ReadBool(const base::win::RegKey& key, const base::char16* name) {
+  DWORD value = 0;
+  return key.ReadValueDW(name, &value) == ERROR_SUCCESS && value != 0;
+}
+
 }  // namespace
 
 void InitializePreReadOptions(const base::string16& product_registry_path) {
@@ -57,27 +67,13 @@ void InitializePreReadOptions(const base::string16& product_registry_path) {
                               KEY_QUERY_VALUE);
 
   // Set the PreRead field trial's options.
-  struct {
-    const base::char16* name;
-    bool* option;
-  } const variations_mappings[] = {
-      {kNoPreReadVariationName, &g_pre_read_options.no_pre_read},
-      {kHighPriorityVariationName, &g_pre_read_options.high_priority},
-      {kOnlyIfColdVariationName, &g_pre_read_options.only_if_cold},
-      {kPrefetchVirtualMemoryVariationName,
-       &g_pre_read_options.prefetch_virtual_memory},
-  };
-
-  for (const auto& mapping : variations_mappings) {
-    // Set the option variable to true if the corresponding value is found in
-    // the registry. Set to false otherwise (default behavior).
-    DWORD value = 0;
-    if (key.ReadValueDW(mapping.name, &value) == ERROR_SUCCESS) {
-      DCHECK_EQ(1U, value);
-      DCHECK(!*mapping.option);
-      *mapping.option = true;
-    }
-  }
+  g_pre_read_options.pre_read = !ReadBool(key, kNoPreReadVariationName);
+  g_pre_read_options.high_priority = ReadBool(key, kHighPriorityVariationName);
+  g_pre_read_options.only_if_cold = ReadBool(key, kOnlyIfColdVariationName);
+  g_pre_read_options.prefetch_virtual_memory =
+      ReadBool(key, kPrefetchVirtualMemoryVariationName);
+  g_pre_read_options.use_prefetch_argument =
+      !ReadBool(key, kNoPrefetchArgumentVariationName);
 }
 
 PreReadOptions GetPreReadOptions() {
diff --git a/components/startup_metric_utils/common/pre_read_field_trial_utils_win.h b/components/startup_metric_utils/common/pre_read_field_trial_utils_win.h
index cacf4b3..a2aaf4a 100644
--- a/components/startup_metric_utils/common/pre_read_field_trial_utils_win.h
+++ b/components/startup_metric_utils/common/pre_read_field_trial_utils_win.h
@@ -21,8 +21,8 @@ using RegisterPreReadSyntheticFieldTrialCallback =
 
 // The options controlled by the PreRead field trial.
 struct PreReadOptions {
-  // No explicit DLL pre-reading.
-  bool no_pre_read;
+  // Pre-read DLLs explicitly.
+  bool pre_read;
 
   // Pre-read DLLs with a high thread priority.
   bool high_priority;
@@ -32,6 +32,9 @@ struct PreReadOptions {
 
   // Pre-read DLLs using the ::PrefetchVirtualMemory function, if available.
   bool prefetch_virtual_memory;
+
+  // Use a /prefetch argument when launching a process.
+  bool use_prefetch_argument;
 };
 
 // Initializes DLL pre-reading options from the registry.
diff --git a/content/browser/gpu/gpu_process_host.cc b/content/browser/gpu/gpu_process_host.cc
index ad9cafe..b3bd310 100644
--- a/content/browser/gpu/gpu_process_host.cc
+++ b/content/browser/gpu/gpu_process_host.cc
@@ -1030,6 +1030,11 @@ bool GpuProcessHost::LaunchGpuProcess(const std::string& channel_id) {
   cmd_line->AppendSwitchASCII(switches::kProcessType, switches::kGpuProcess);
   cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id);
 
+#if defined(OS_WIN)
+  if (GetContentClient()->browser()->ShouldUseWindowsPrefetchArgument())
+    cmd_line->AppendArg(switches::kPrefetchArgumentGpu);
+#endif  // defined(OS_WIN)
+
   if (kind_ == GPU_PROCESS_KIND_UNSANDBOXED)
     cmd_line->AppendSwitch(switches::kDisableGpuSandbox);
 
diff --git a/content/browser/plugin_process_host.cc b/content/browser/plugin_process_host.cc
index 9ede7a2..cb14fa7 100644
--- a/content/browser/plugin_process_host.cc
+++ b/content/browser/plugin_process_host.cc
@@ -209,6 +209,11 @@ bool PluginProcessHost::Init(const WebPluginInfo& info) {
   cmd_line->AppendSwitchASCII(switches::kProcessType, switches::kPluginProcess);
   cmd_line->AppendSwitchPath(switches::kPluginPath, info.path);
 
+#if defined(OS_WIN)
+  if (GetContentClient()->browser()->ShouldUseWindowsPrefetchArgument())
+    cmd_line->AppendArg(switches::kPrefetchArgumentOther);
+#endif  // defined(OS_WIN)
+
   // Propagate the following switches to the plugin command line (along with
   // any associated values) if present in the browser command line
   static const char* const kSwitchNames[] = {
diff --git a/content/browser/ppapi_plugin_process_host.cc b/content/browser/ppapi_plugin_process_host.cc
index e17b694..3523fc1 100644
--- a/content/browser/ppapi_plugin_process_host.cc
+++ b/content/browser/ppapi_plugin_process_host.cc
@@ -373,6 +373,13 @@ bool PpapiPluginProcessHost::Init(const PepperPluginInfo& info) {
                                          : switches::kPpapiPluginProcess);
   cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id);
 
+#if defined(OS_WIN)
+  if (GetContentClient()->browser()->ShouldUseWindowsPrefetchArgument()) {
+    cmd_line->AppendArg(is_broker_ ? switches::kPrefetchArgumentPpapiBroker
+                                   : switches::kPrefetchArgumentPpapi);
+  }
+#endif  // defined(OS_WIN)
+
   // These switches are forwarded to both plugin and broker pocesses.
   static const char* kCommonForwardSwitches[] = {
     switches::kVModule
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index bfba388..667dc22 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -1291,6 +1291,11 @@ void RenderProcessHostImpl::AppendRendererCommandLine(
   command_line->AppendSwitchASCII(switches::kProcessType,
                                   switches::kRendererProcess);
 
+#if defined(OS_WIN)
+  if (GetContentClient()->browser()->ShouldUseWindowsPrefetchArgument())
+    command_line->AppendArg(switches::kPrefetchArgumentRenderer);
+#endif  // defined(OS_WIN)
+
   // Now send any options from our own command line we want to propagate.
   const base::CommandLine& browser_command_line =
       *base::CommandLine::ForCurrentProcess();
diff --git a/content/browser/utility_process_host_impl.cc b/content/browser/utility_process_host_impl.cc
index db67d60..42c31bd 100644
--- a/content/browser/utility_process_host_impl.cc
+++ b/content/browser/utility_process_host_impl.cc
@@ -286,6 +286,11 @@ bool UtilityProcessHostImpl::StartProcess() {
     std::string locale = GetContentClient()->browser()->GetApplicationLocale();
     cmd_line->AppendSwitchASCII(switches::kLang, locale);
 
+#if defined(OS_WIN)
+    if (GetContentClient()->browser()->ShouldUseWindowsPrefetchArgument())
+      cmd_line->AppendArg(switches::kPrefetchArgumentOther);
+#endif  // defined(OS_WIN)
+
     if (no_sandbox_)
       cmd_line->AppendSwitch(switches::kNoSandbox);
 
diff --git a/content/common/sandbox_win.cc b/content/common/sandbox_win.cc
index 5230738..92a5a24 100644
--- a/content/common/sandbox_win.cc
+++ b/content/common/sandbox_win.cc
@@ -681,11 +681,6 @@ base::Process StartSandboxedProcess(
 
   ProcessDebugFlags(cmd_line);
 
-  // Prefetch hints on windows:
-  // Using a different prefetch profile per process type will allow Windows
-  // to create separate pretetch settings for browser, renderer etc.
-  cmd_line->AppendArg(base::StringPrintf("/prefetch:%d", base::Hash(type_str)));
-
   if ((!delegate->ShouldSandbox()) ||
       browser_command_line.HasSwitch(switches::kNoSandbox) ||
       cmd_line->HasSwitch(switches::kNoSandbox)) {
diff --git a/content/public/browser/content_browser_client.cc b/content/public/browser/content_browser_client.cc
index 121f7c2..3f6d970 100644
--- a/content/public/browser/content_browser_client.cc
+++ b/content/public/browser/content_browser_client.cc
@@ -418,7 +418,11 @@ bool ContentBrowserClient::IsWin32kLockdownEnabledForMimeType(
   // is enabled by default in Chrome. See crbug.com/523278.
   return false;
 }
-#endif
+
+bool ContentBrowserClient::ShouldUseWindowsPrefetchArgument() const {
+  return true;
+}
+#endif  // defined(OS_WIN)
 
 #if defined(VIDEO_HOLE)
 ExternalVideoSurfaceContainer*
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index b19adfb..5ecc56e 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -756,6 +756,10 @@ class CONTENT_EXPORT ContentBrowserClient {
   // a process hosting a plugin with the specified |mime_type|.
   virtual bool IsWin32kLockdownEnabledForMimeType(
       const std::string& mime_type) const;
+
+  // Returns true if processes should be launched with a /prefetch:# argument.
+  // See the kPrefetchArgument* constants in content_switches.cc for details.
+  virtual bool ShouldUseWindowsPrefetchArgument() const;
 #endif
 
 #if defined(VIDEO_HOLE)
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 1fe03b0..094ecf1 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -968,6 +968,30 @@ const char kDisableCoreAnimationPlugins[] =
 #endif
 
 #if defined(OS_WIN)
+// /prefetch:# arguments to use when launching various process types. It has
+// been observed that when file reads are consistent for 3 process launches with
+// the same /prefetch:# argument, the Windows prefetcher starts issuing reads in
+// batch at process launch. Because reads depend on the process type, the
+// prefetcher wouldn't be able to observe consistent reads if no /prefetch:#
+// arguments were used. Note that the browser process has no /prefetch:#
+// argument; as such all other processes must have one in order to avoid
+// polluting its profile. Note: # must always be in [1, 8]; otherwise it is
+// ignored by the Windows prefetcher.
+const char kPrefetchArgumentRenderer[] = "/prefetch:1";
+const char kPrefetchArgumentGpu[] = "/prefetch:2";
+const char kPrefetchArgumentPpapi[] = "/prefetch:3";
+const char kPrefetchArgumentPpapiBroker[] = "/prefetch:4";
+// /prefetch:5, /prefetch:6 and /prefetch:7 are reserved for content embedders
+// and are not to be used by content itself.
+
+// /prefetch:# argument shared by all process types that don't have their own.
+// It is likely that the prefetcher won't work for these process types as it
+// won't be able to observe consistent file reads across launches. However,
+// having a valid prefetch argument for these process types is required to
+// prevent them from interfering with the prefetch profile of the browser
+// process.
+const char kPrefetchArgumentOther[] = "/prefetch:8";
+
 // Device scale factor passed to certain processes like renderers, etc.
 const char kDeviceScaleFactor[]     = "device-scale-factor";
 
diff --git a/content/public/common/content_switches.h b/content/public/common/content_switches.h
index 1174c61..f45e539 100644
--- a/content/public/common/content_switches.h
+++ b/content/public/common/content_switches.h
@@ -291,6 +291,11 @@ extern const char kDisableThreadedEventHandlingMac[];
 #endif
 
 #if defined(OS_WIN)
+CONTENT_EXPORT extern const char kPrefetchArgumentRenderer[];
+CONTENT_EXPORT extern const char kPrefetchArgumentGpu[];
+CONTENT_EXPORT extern const char kPrefetchArgumentPpapi[];
+CONTENT_EXPORT extern const char kPrefetchArgumentPpapiBroker[];
+CONTENT_EXPORT extern const char kPrefetchArgumentOther[];
 // This switch contains the device scale factor passed to certain processes
 // like renderers, etc.
 CONTENT_EXPORT extern const char kDeviceScaleFactor[];