DevTools window doesn't restore its minimal size if it's shrinked to zero.

chrome/browser/ui/browser.cc

 // Copyright (c) 2011 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 "chrome/browser/ui/browser.h"
 
 #if defined(OS_WIN)
 #include <shellapi.h>
 #include <windows.h>
 #endif  // OS_WIN
@@ skipping 2208 matching lines @@
   prefs->RegisterBooleanPref(prefs::kCloudPrintProxyEnabled,
                              true,
                              PrefService::UNSYNCABLE_PREF);
   prefs->RegisterBooleanPref(prefs::kDevToolsDisabled,
                              false,
                              PrefService::UNSYNCABLE_PREF);
   prefs->RegisterBooleanPref(prefs::kIncognitoEnabled,
                              true,
                              PrefService::UNSYNCABLE_PREF);
   prefs->RegisterIntegerPref(prefs::kDevToolsSplitLocation,
-                             -1,
+                             400,
                              PrefService::UNSYNCABLE_PREF);
   prefs->RegisterDictionaryPref(prefs::kBrowserWindowPlacement,
                                 PrefService::UNSYNCABLE_PREF);
   prefs->RegisterDictionaryPref(prefs::kPreferencesWindowPlacement,
                                 PrefService::UNSYNCABLE_PREF);
   // We need to register the type of these preferences in order to query
   // them even though they're only typically controlled via policy.
   prefs->RegisterBooleanPref(prefs::kDisable3DAPIs,
                              false,
                              PrefService::UNSYNCABLE_PREF);
@@ skipping 2455 matching lines @@
   TabContents* current_tab = GetSelectedTabContents();
   if (current_tab) {
     content_restrictions = current_tab->content_restrictions();
     NavigationEntry* active_entry = current_tab->controller().GetActiveEntry();
     // See comment in UpdateCommandsForTabState about why we call url().
     if (!SavePackage::IsSavableURL(active_entry ? active_entry->url() : GURL()))
       content_restrictions |= CONTENT_RESTRICTION_SAVE;
   }
   return content_restrictions;
 }