mojo: Improve crash stack.

mojo/runner/host/child_process.cc

 // Copyright 2014 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 "mojo/runner/host/child_process.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
+#include "base/debug/stack_trace.h"
 #include "base/files/file_path.h"
 #include "base/i18n/icu_util.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/waitable_event.h"
@@ skipping 331 matching lines @@
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
 
 #if defined(OS_LINUX) && !defined(OS_ANDROID)
   scoped_ptr<mojo::runner::LinuxSandbox> sandbox;
 #endif
   base::NativeLibrary app_library = 0;
   // Load the application library before we engage the sandbox.
   app_library = mojo::runner::LoadNativeApplication(
       command_line.GetSwitchValuePath(switches::kChildProcess));
-
   base::i18n::InitializeICU();
   if (app_library)
     CallLibraryEarlyInitialization(app_library);
 #if defined(OS_LINUX) && !defined(OS_ANDROID)
-  if (command_line.HasSwitch(switches::kEnableSandbox))
+  if (command_line.HasSwitch(switches::kEnableSandbox)) {
+#if !defined(OFFICIAL_BUILD)
+    // Initialize stack dumping just before initializing sandbox to make
+    // sure symbol names in all loaded libraries will be cached.
+    base::debug::EnableInProcessStackDumping();
+#endif
     sandbox = InitializeSandbox();
+  }
 #endif
 
   embedder::ScopedPlatformHandle platform_channel =
       embedder::PlatformChannelPair::PassClientHandleFromParentProcess(
           command_line);
   CHECK(platform_channel.is_valid());
 
   DCHECK(!base::MessageLoop::current());
 
   AppContext app_context;
   app_context.Init();
   ScopedMessagePipeHandle host_message_pipe = InitializeHostMessagePipe(
       platform_channel.Pass(), app_context.io_runner());
   Blocker blocker;
   app_context.controller_runner()->PostTask(
       FROM_HERE,
       base::Bind(&ChildControllerImpl::Init, base::Unretained(&app_context),
                  base::Unretained(app_library),
                  base::Passed(&host_message_pipe), blocker.GetUnblocker()));
   // This will block, then run whatever the controller wants.
   blocker.Block();
 
   app_context.Shutdown();
 
   return 0;
 }
 
 }  // namespace runner
 }  // namespace mojo