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

chrome/common/pref_names.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/common/pref_names.h"
 
 namespace prefs {
 
 // *************** PROFILE PREFS ***************
 // These are attached to the user profile
@@ skipping 1156 matching lines @@
 const char kGpuBlacklistUpdate[] = "gpu_blacklist_update";
 
 const char kDevToolsDisabled[] = "devtools.disabled";
 
 // A boolean specifying whether dev tools window should be opened docked.
 const char kDevToolsOpenDocked[] = "devtools.open_docked";
 
 // Integer location of the split bar in the browser view.
 const char kDevToolsSplitLocation[] = "devtools.split_location";
 
+// Integer height of the devtools widget in the browser view.
+const char kDevToolsWidgetHeight[] = "devtools.widget_height";
+
 // 64-bit integer serialization of the base::Time when the last sync occurred.
 const char kSyncLastSyncedTime[] = "sync.last_synced_time";
 
 // Boolean specifying whether the user finished setting up sync.
 const char kSyncHasSetupCompleted[] = "sync.has_setup_completed";
 
 // Boolean specifying whether to automatically sync all data types (including
 // future ones, as they're added).  If this is true, the following preferences
 // (kSyncBookmarks, kSyncPasswords, etc.) can all be ignored.
 const char kKeepEverythingSynced[] = "sync.keep_everything_synced";
@@ skipping 185 matching lines @@
 // Whether user-specified handlers for protocols and content types can be
 // specified.
 const char kCustomHandlersEnabled[] = "custom_handlers.enabled";
 
 // Integers that specify the policy refresh rate for device- and user-policy in
 // milliseconds. Not all values are meaningful, so it is clamped to a sane range
 // by the cloud policy subsystem.
 const char kDevicePolicyRefreshRate[] = "policy.device_refresh_rate";
 const char kUserPolicyRefreshRate[] = "policy.user_refresh_rate";
 }  // namespace prefs