Add the ability to load multiple apps into app_shell.

extensions/shell/browser/default_shell_browser_main_delegate.cc

Index: extensions/shell/browser/default_shell_browser_main_delegate.cc
diff --git a/extensions/shell/browser/default_shell_browser_main_delegate.cc b/extensions/shell/browser/default_shell_browser_main_delegate.cc
index 491fe4370324a1e5d70243477782fd304cf63a61..03502170982bc75ed5c79c672ff4845824745efe 100644
--- a/extensions/shell/browser/default_shell_browser_main_delegate.cc
+++ b/extensions/shell/browser/default_shell_browser_main_delegate.cc
@@ -7,6 +7,7 @@
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
+#include "base/strings/string_tokenizer.h"
 #include "extensions/shell/browser/shell_desktop_controller.h"
 #include "extensions/shell/browser/shell_extension_system.h"
 #include "extensions/shell/common/switches.h"
@@ -23,15 +24,24 @@ void DefaultShellBrowserMainDelegate::Start(
     content::BrowserContext* browser_context) {
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(switches::kAppShellAppPath)) {
-    base::FilePath app_dir(
-        command_line->GetSwitchValueNative(switches::kAppShellAppPath));
-    base::FilePath app_absolute_dir = base::MakeAbsoluteFilePath(app_dir);
-
     ShellExtensionSystem* extension_system = static_cast<ShellExtensionSystem*>(
         ExtensionSystem::Get(browser_context));
-    if (!extension_system->LoadApp(app_absolute_dir))
-      return;
-    extension_system->LaunchApp();
+    CommandLine::StringType path_list =
+        command_line->GetSwitchValueNative(switches::kAppShellAppPath);
+
+    base::StringTokenizerT<CommandLine::StringType,
+                           CommandLine::StringType::const_iterator>
+        t(path_list, FILE_PATH_LITERAL(","));
+    extension_system->Init();
+    while (t.GetNext()) {
+      base::FilePath app_absolute_dir =
+          base::MakeAbsoluteFilePath(base::FilePath(t.token()));
+
+      const Extension* extension = extension_system->LoadApp(app_absolute_dir);
+      if (!extension)
+        continue;
+      extension_system->LaunchApp(extension->id());
+    }
   } else {
     LOG(ERROR) << "--" << switches::kAppShellAppPath
                << " unset; boredom is in your future";