Make the shell work in multiprocess mode some apps.

shell/desktop/mojo_main.cc

 // Copyright 2013 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 <algorithm>
 #include <iostream>
 
 #include "base/at_exit.h"
 #include "base/base_switches.h"
 #include "base/bind.h"
@@ skipping 33 matching lines @@
       << "text/html,mojo:html_viewer,"
       << "application/javascript,mojo:js_content_handler\n";
 }
 
 }  // namespace
 
 int main(int argc, char** argv) {
   base::AtExitManager at_exit;
   base::CommandLine::Init(argc, argv);
 
-  const base::CommandLine& command_line =
-      *base::CommandLine::ForCurrentProcess();
-
-  const std::set<std::string> all_switches = switches::GetAllSwitches();
-  const base::CommandLine::SwitchMap switches = command_line.GetSwitches();
-  bool found_unknown_switch = false;
-  for (const auto& s : switches) {
-    if (all_switches.find(s.first) == all_switches.end()) {
-      std::cerr << "unknown switch: " << s.first << std::endl;
-      found_unknown_switch = true;
-    }
-  }
-
-  if (found_unknown_switch ||
-      (!command_line.HasSwitch(switches::kEnableExternalApplications) &&
-       (command_line.HasSwitch(switches::kHelp) ||
-        command_line.GetArgs().empty()))) {
-    Usage();
-    return 0;
-  }
-
-#if defined(OS_LINUX)
-  // We use gfx::RenderText from multiple threads concurrently and the pango
-  // backend (currently the default on linux) is not close to threadsafe. Force
-  // use of the harfbuzz backend for now.
-  base::CommandLine::ForCurrentProcess()->AppendSwitch(
-      kEnableHarfBuzzRenderText);
-#endif
   mojo::shell::InitializeLogging();
 
   // TODO(vtl): Unify parent and child process cases to the extent possible.
   if (scoped_ptr<mojo::shell::ChildProcess> child_process =
           mojo::shell::ChildProcess::Create(
               *base::CommandLine::ForCurrentProcess())) {
     child_process->Main();
   } else {
+    // Only check the command line for the main process.
+    const base::CommandLine& command_line =
+        *base::CommandLine::ForCurrentProcess();
+
+    const std::set<std::string> all_switches = switches::GetAllSwitches();
+    const base::CommandLine::SwitchMap switches = command_line.GetSwitches();
+    bool found_unknown_switch = false;
+    for (const auto& s : switches) {
+      if (all_switches.find(s.first) == all_switches.end()) {
+        std::cerr << "unknown switch: " << s.first << std::endl;
+        found_unknown_switch = true;
+      }
+    }
+
+    if (found_unknown_switch ||
+        (!command_line.HasSwitch(switches::kEnableExternalApplications) &&
+         (command_line.HasSwitch(switches::kHelp) ||
+          command_line.GetArgs().empty()))) {
+      Usage();
+      return 0;
+    }
+
+#if defined(OS_LINUX)
+    // We use gfx::RenderText from multiple threads concurrently and the pango
+    // backend (currently the default on linux) is not close to threadsafe.
+    // Force use of the harfbuzz backend for now.
+    base::CommandLine::ForCurrentProcess()->AppendSwitch(
+        kEnableHarfBuzzRenderText);
+#endif
+
     // We want the shell::Context to outlive the MessageLoop so that pipes are
     // all gracefully closed / error-out before we try to shut the Context down.
     mojo::shell::Context shell_context;
     {
       base::MessageLoop message_loop;
       if (!shell_context.Init()) {
         Usage();
         return 0;
       }
 
       // The mojo_shell --args-for command-line switch is handled specially
       // because it can appear more than once. The base::CommandLine class
       // collapses multiple occurrences of the same switch.
       for (int i = 1; i < argc; i++) {
         ApplyApplicationArgs(&shell_context, argv[i]);
       }
 
       message_loop.PostTask(
           FROM_HERE,
           base::Bind(&mojo::shell::RunCommandLineApps, &shell_context));
       message_loop.Run();
 
       // Must be called before |message_loop| is destroyed.
       shell_context.Shutdown();
     }
   }
   return 0;
 }