Refactor ProcessSingleton so that it may be used distinctly from a full browser process.

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 97de7c0c1f46bc0231da17fcf72d7a6ee4554932..c4c5b75c9c0ea103f12d0b8c72583133d51ee07d 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -31,6 +31,7 @@
 #include "chrome/browser/about_flags.h"
 #include "chrome/browser/auto_launch_trial.h"
 #include "chrome/browser/autocomplete/autocomplete_field_trial.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_process_impl.h"
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/chrome_browser_main_extra_parts.h"
@@ -538,6 +539,52 @@ void AddPreReadHistogramTime(const char* name, base::TimeDelta time) {
   counter->AddTime(time);
 }
 
+bool ProcessSingletonNotificationCallback(const CommandLine& command_line,
+                                          const FilePath& current_directory) {
+  // Drop the request if the browser process is already in shutdown path.
+  if (!g_browser_process || g_browser_process->IsShuttingDown())
+    return false;
+
+  PrefService* prefs = g_browser_process->local_state();

[jam, 2012/04/04 00:44:44]

nit: this isn't used

[erikwright (departed), 2012/04/04 02:51:48]

This is migrated here from process_singleton_linux.cc . I suspect that it was a
diagnostic step. I will find the original committer, ask if it is still
required, and either remove it or add an explanatory comment.

[erikwright (departed), 2012/04/04 14:51:28]

Actually, it was in both the linux and windows versions. I tracked it down.
Previously BrowserInit::ProcessCommandLine took the PrefService as a parameter,
but you removed the parameter in this CL without removing the access:

http://codereview.chromium.org/43035

+  DCHECK(prefs);
+
+  // Handle the --uninstall-extension startup action. This needs to done here
+  // in the process that is running with the target profile, otherwise the
+  // uninstall will fail to unload and remove all components.
+  if (command_line.HasSwitch(switches::kUninstallExtension)) {
+    // The uninstall extension switch can't be combined with the profile
+    // directory switch.
+    DCHECK(!command_line.HasSwitch(switches::kProfileDirectory));
+
+    Profile* profile = ProfileManager::GetLastUsedProfile();
+    if (!profile) {
+      // We should only be able to get here if the profile already exists and
+      // has been created.

[robertshield, 2012/04/04 01:07:15]

I'm curious about this comment: does the profile already existing really imply
that GetLastUsedProfile() should return NULL?

[erikwright (departed), 2012/04/04 02:51:48]

This comment may be misleading. I believe "here" refers to "receiving a
notification in ProcessSingleton", not "the inside of this particular 'if
(!profile) {' condition".

+      NOTREACHED();
+      return true;
+    }
+
+    ExtensionsStartupUtil ext_startup_util;
+    ext_startup_util.UninstallExtension(command_line, profile);
+    return true;
+  }
+
+  // Ignore the request if the process was passed the --product-version flag.
+  // Normally we wouldn't get here if that flag had been passed, but it can
+  // happen if it is passed to an older version of chrome. Since newer versions
+  // of chrome do this in the background, we want to avoid spawning extra
+  // windows.
+  if (command_line.HasSwitch(switches::kProductVersion)) {
+    DLOG(WARNING) << "Remote process was passed product version flag, "
+                  << "but ignored it. Doing nothing.";
+    return true;
+  }
+
+  BrowserInit::ProcessCommandLineAlreadyRunning(
+      command_line, current_directory);
+  return true;
+}
+
 }  // namespace
 
 namespace chrome_browser {
@@ -1465,7 +1512,8 @@ int ChromeBrowserMainParts::PreMainMessageLoopRunImpl() {
     // new one. NotifyOtherProcess will currently give the other process up to
     // 20 seconds to respond. Note that this needs to be done before we attempt
     // to read the profile.
-    notify_result_ = process_singleton_->NotifyOtherProcessOrCreate();
+    notify_result_ = process_singleton_->NotifyOtherProcessOrCreate(
+        base::Bind(&ProcessSingletonNotificationCallback));
     switch (notify_result_) {
       case ProcessSingleton::PROCESS_NONE:
         // No process already running, fall through to starting a new one.