Add --auto-open-devtools-for-tabs flag.

chrome/browser/browser_process_impl.cc

Index: chrome/browser/browser_process_impl.cc
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index 45756a4d69837af8358fad6ebd90e36bff2d0637..9f17e38602bd98c6c6d9a78dc1a85366f7cd3422 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -35,6 +35,7 @@
 #include "chrome/browser/component_updater/chrome_component_updater_configurator.h"
 #include "chrome/browser/component_updater/supervised_user_whitelist_installer.h"
 #include "chrome/browser/defaults.h"
+#include "chrome/browser/devtools/devtools_auto_opener.h"
 #include "chrome/browser/devtools/remote_debugging_server.h"
 #include "chrome/browser/download/download_request_limiter.h"
 #include "chrome/browser/download/download_status_updater.h"
@@ -286,6 +287,7 @@ void BrowserProcessImpl::StartTearDown() {
 #if !defined(OS_ANDROID)
   // Debugger must be cleaned up before ProfileManager.
   remote_debugging_server_.reset();
+  devtools_auto_opener_.reset();
 #endif
 
   // Need to clear profiles (download managers) before the io_thread_.
@@ -688,6 +690,16 @@ void BrowserProcessImpl::CreateDevToolsHttpProtocolHandler(
 #endif
 }
 
+void BrowserProcessImpl::CreateDevToolsAutoOpener() {
+  DCHECK(CalledOnValidThread());
+#if !defined(OS_ANDROID)
+  // StartupBrowserCreator::LaunchBrowser can be run multiple times when browser
+  // is started with several profiles or existing browser process is reused.
+  if (!devtools_auto_opener_.get())
+    devtools_auto_opener_.reset(new DevToolsAutoOpener());
+#endif
+}
+
 bool BrowserProcessImpl::IsShuttingDown() {
   DCHECK(CalledOnValidThread());
   // TODO(crbug.com/560486): Fix the tests that make the check of