Removes --enable-stacked-tab-strip flag (Stacked Tabs)

chrome/browser/ui/tabs/tab_strip_layout_type_prefs.cc

 // Copyright (c) 2012 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/tabs/tab_strip_layout_type_prefs.h"
 
 #include "base/prefs/pref_registry_simple.h"
-#include "chrome/browser/ui/tabs/tab_strip_layout_type.h"
+#include "base/prefs/pref_service.h"
 #include "chrome/common/pref_names.h"
 
 namespace chrome {
 
-void RegisterTabStripLayoutTypePrefs(PrefRegistrySimple* registry) {
-  // This value is device dependant, so it goes in local state.
-  registry->RegisterIntegerPref(prefs::kTabStripLayoutType,
-                                static_cast<int>(TAB_STRIP_LAYOUT_SHRINK));
+// The following values are persisted in prefs:
+// 0 - Tabs shrink to accommodate the available space. This is the default.
+// 1 - The tabs are always sized to their ideal size and stacked on top of each
+//     other so that only a certain set of tabs are visible. This is used when
+//     the user uses a touch device.

[Peter Kasting, 2014/05/23 17:48:46]

Don't use an integer pref for this, use a boolean pref.  Name the pref something
like kAllowStackedTabs.

Once this is done, all this documentation is unnecessary, and this whole file
should go away; BrowserTabStripController can just read/write the prefs
directly.

[varkha, 2014/05/23 17:51:57]

That would be great but don't we want to preserve existing user settings?

[varkha, 2014/05/23 21:45:48]

Done. The file is still there (unmodified) since it has a registration call.

+
+void TabStripLayoutTypePrefs::Register(PrefRegistrySimple* registry) {
+  // This value is device dependent, so it goes in local state.
+  // 0 is the default (not stacked) layout type in prefs.
+  registry->RegisterIntegerPref(prefs::kTabStripLayoutType, 0);
+}
+
+bool TabStripLayoutTypePrefs::GetStackedLayout(PrefService* prefs) {
+  return prefs->GetInteger(prefs::kTabStripLayoutType) != 0;
+}
+
+void TabStripLayoutTypePrefs::SetStackedLayout(PrefService* prefs,
+                                               bool stacked_layout) {
+  prefs->SetInteger(prefs::kTabStripLayoutType, stacked_layout ? 0 : 1);

[Peter Kasting, 2014/05/23 17:48:46]

Isn't this backwards?  Using a bool pref with a good name would make this clear.

[varkha, 2014/05/23 21:45:48]

Exactly! That's why getting rid of this in favour of a bool pref is a good idea.

 }
 
 }  // namespace chrome