Simplify some mojo_shell code.

mojo/shell/desktop/launcher_process.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 <stdio.h>
 #include <string.h>
 
 #include <algorithm>
 #include <iostream>
 
-#include "base/at_exit.h"
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/trace_event/trace_event.h"
-#include "mojo/shell/child_process.h"
 #include "mojo/shell/command_line_util.h"
 #include "mojo/shell/context.h"
-#include "mojo/shell/init.h"
 #include "mojo/shell/switches.h"
 
+namespace mojo {
+namespace shell {
 namespace {
 
 void Usage() {
   std::cerr << "Launch Mojo applications.\n";
   std::cerr
       << "Usage: mojo_shell"
       << " [--" << switches::kArgsFor << "=<mojo-app>]"
       << " [--" << switches::kContentHandlers << "=<handlers>]"
-      << " [--" << switches::kEnableExternalApplications << "]"
       << " [--" << switches::kDisableCache << "]"
       << " [--" << switches::kEnableMultiprocess << "]"
       << " [--" << switches::kOrigin << "=<url-lib-path>]"
       << " [--" << switches::kTraceStartup << "]"
       << " [--" << switches::kURLMappings << "=from1=to1,from2=to2]"
       << " [--" << switches::kPredictableAppFilenames << "]"
       << " [--" << switches::kWaitForDebugger << "]"
       << " <mojo-app> ...\n\n"
       << "A <mojo-app> is a Mojo URL or a Mojo URL and arguments within "
       << "quotes.\n"
@@ skipping 52 matching lines @@
   base::Thread flush_thread("mojo_shell_trace_event_flush");
   flush_thread.Start();
   flush_thread.message_loop()->PostTask(
       FROM_HERE,
       base::Bind(EndTraceAndFlush, base::Unretained(&flush_complete_event)));
   flush_complete_event.Wait();
 }
 
 }  // namespace
 
-int main(int argc, char** argv) {
-  base::AtExitManager at_exit;
-  base::CommandLine::Init(argc, argv);
+int LauncherProcessMain(int argc, char** argv) {
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
 
-  mojo::shell::InitializeLogging();
+  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;
+    }
+  }
 
-  // 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();
+  if (found_unknown_switch || command_line.HasSwitch(switches::kHelp) ||
+      command_line.GetArgs().empty()) {
+    Usage();
+    return 0;
+  }
 
-    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 (command_line.HasSwitch(switches::kTraceStartup)) {
+    g_tracing = true;
+    base::trace_event::CategoryFilter category_filter(
+        command_line.GetSwitchValueASCII(switches::kTraceStartup));
+    base::trace_event::TraceLog::GetInstance()->SetEnabled(
+        category_filter, base::trace_event::TraceLog::RECORDING_MODE,
+        base::trace_event::TraceOptions(base::trace_event::RECORD_UNTIL_FULL));
+  }
 
-    if (found_unknown_switch ||
-        (!command_line.HasSwitch(switches::kEnableExternalApplications) &&
-         (command_line.HasSwitch(switches::kHelp) ||
-          command_line.GetArgs().empty()))) {
+  // 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;
     }
-
-    if (command_line.HasSwitch(switches::kTraceStartup)) {
-      g_tracing = true;
-      base::trace_event::CategoryFilter category_filter(
-          command_line.GetSwitchValueASCII(switches::kTraceStartup));
-      base::trace_event::TraceLog::GetInstance()->SetEnabled(
-          category_filter, base::trace_event::TraceLog::RECORDING_MODE,
-          base::trace_event::TraceOptions(
-              base::trace_event::RECORD_UNTIL_FULL));
+    if (g_tracing) {
+      message_loop.PostDelayedTask(FROM_HERE,
+                                   base::Bind(StopTracingAndFlushToDisk),
+                                   base::TimeDelta::FromSeconds(5));
     }
 
-    // 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;
-      }
-      if (g_tracing) {
-        message_loop.PostDelayedTask(FROM_HERE,
-                                     base::Bind(StopTracingAndFlushToDisk),
-                                     base::TimeDelta::FromSeconds(5));
-      }
+    // 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]);
+    }
 
-      // 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();
 
-      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();
-    }
+    // Must be called before |message_loop| is destroyed.
+    shell_context.Shutdown();
   }
 
   if (g_tracing)
     StopTracingAndFlushToDisk();
   return 0;
 }
+
+}  // namespace shell
+}  // namespace mojo