Experiment to hide close buttons of inactive tabs when using touch

chrome/browser/ui/tabs/tab_utils.cc

Index: chrome/browser/ui/tabs/tab_utils.cc
diff --git a/chrome/browser/ui/tabs/tab_utils.cc b/chrome/browser/ui/tabs/tab_utils.cc
index 1f17621f9057367f076a8a60bfc4a6d613ac76b8..a90b0bc4f494cf4ed47ba046129d432633b60d57 100644
--- a/chrome/browser/ui/tabs/tab_utils.cc
+++ b/chrome/browser/ui/tabs/tab_utils.cc
@@ -9,6 +9,7 @@
 #include "chrome/browser/media/media_capture_devices_dispatcher.h"
 #include "chrome/browser/media/media_stream_capture_indicator.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/browser/ui/views/tabs/tab.h"

[tdanderson, 2015/02/06 20:34:33]

I added this so that I can access the static methods in Tab which give the
ideal/touch widths, but this is a violation of the include rules. Can you
suggest the best way to make the width information available?

[tdanderson, 2015/02/10 18:52:17]

No longer an issue since I've moved the new logic into Tab.

 #include "chrome/common/chrome_switches.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/browser/web_contents.h"
@@ -80,6 +81,8 @@ TabRecordingIndicatorAnimation::Create() {
 }  // namespace
 
 bool ShouldTabShowFavicon(int capacity,
+                          int width,
+                          bool touch_used_last,
                           bool is_pinned_tab,
                           bool is_active_tab,
                           bool has_favicon,
@@ -87,36 +90,67 @@ bool ShouldTabShowFavicon(int capacity,
   if (!has_favicon)
     return false;
   int required_capacity = 1;
-  if (ShouldTabShowCloseButton(capacity, is_pinned_tab, is_active_tab))
+  if (ShouldTabShowCloseButton(capacity,
+                               width,
+                               touch_used_last,
+                               is_pinned_tab,
+                               is_active_tab)) {
     ++required_capacity;
-  if (ShouldTabShowMediaIndicator(
-          capacity, is_pinned_tab, is_active_tab, has_favicon, media_state)) {
+  }
+  if (ShouldTabShowMediaIndicator(capacity,
+                                  width,
+                                  touch_used_last,
+                                  is_pinned_tab,
+                                  is_active_tab,
+                                  has_favicon,
+                                  media_state)) {
     ++required_capacity;
   }
   return capacity >= required_capacity;
 }
 
 bool ShouldTabShowMediaIndicator(int capacity,
+                                 int width,
+                                 bool touch_used_last,
                                  bool is_pinned_tab,
                                  bool is_active_tab,
                                  bool has_favicon,
                                  TabMediaState media_state) {
   if (media_state == TAB_MEDIA_STATE_NONE)
     return false;
-  if (ShouldTabShowCloseButton(capacity, is_pinned_tab, is_active_tab))
+  if (ShouldTabShowCloseButton(capacity,
+                               width,
+                               touch_used_last,
+                               is_pinned_tab,
+                               is_active_tab)) {
     return capacity >= 2;
+  }
   return capacity >= 1;
 }
 
 bool ShouldTabShowCloseButton(int capacity,
+                              int width,
+                              bool touch_used_last,
                               bool is_pinned_tab,
                               bool is_active_tab) {
   if (is_pinned_tab)
     return false;
   else if (is_active_tab)
     return true;
-  else
-    return capacity >= 3;
+
+  if (touch_used_last) {
+    std::string switch_value =
+        base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+            switches::kTabCloseButtonsHiddenWithTouch);
+    if (switch_value == "always")

[sky, 2015/02/07 00:09:39]

This code is basically saying if touch_used_last (and one of these flags is set)
don't show the close button. That conditional can just as well be moved to views
and don't call this function. Which basically means no changes are necessary
here.

[tdanderson, 2015/02/10 18:52:17]

Done.

+      return false;
+    else if (switch_value == "narrow" && width < Tab::GetStandardSize().width())
+      return false;
+    else if (switch_value == "stacked" && width <= Tab::GetTouchWidth())
+      return false;
+  }
+
+  return capacity >= 3;
 }
 
 bool IsPlayingAudio(content::WebContents* contents) {