[Chrome OS MD] Enable the brightness row to be visible at all times

ash/common/system/chromeos/brightness/tray_brightness.cc

Index: ash/common/system/chromeos/brightness/tray_brightness.cc
diff --git a/ash/common/system/chromeos/brightness/tray_brightness.cc b/ash/common/system/chromeos/brightness/tray_brightness.cc
index cada6c43bf6566ac3efc0a471dbb39658aeb50c5..1b24202012f17d50ceda45796a2cb13c1c4b009e 100644
--- a/ash/common/system/chromeos/brightness/tray_brightness.cc
+++ b/ash/common/system/chromeos/brightness/tray_brightness.cc
@@ -47,6 +47,9 @@ const double kMinBrightnessPercent = 5.0;
 
 }  // namespace
 
+// TODO(yiyix|tdanderson): Once Chrome OS material design is enabled by default,
+// BrightnessView does not need to be a ShellObserver to observe touch view mode
+// changes. See crbug.com/614453.

[tdanderson, 2016/09/12 15:54:49]

Good catch, and thanks for add this TODO.

[yiyix, 2016/09/12 17:31:24]

:) thanks

 class BrightnessView : public ShellObserver,
                        public views::View,
                        public views::SliderListener {
@@ -123,11 +126,16 @@ BrightnessView::BrightnessView(bool default_view, double initial_percent)
       rb.GetLocalizedString(IDS_ASH_STATUS_TRAY_BRIGHTNESS));
   AddChildView(slider_);
 
-  if (is_default_view_) {
-    WmShell::Get()->AddShellObserver(this);
-    SetVisible(WmShell::Get()
-                   ->maximize_mode_controller()
-                   ->IsMaximizeModeWindowManagerEnabled());
+  if (MaterialDesignController::IsSystemTrayMenuMaterial()) {
+    bool show_icon = !icon->GetImage().isNull();

[tdanderson, 2016/09/12 15:54:49]

I don't think this check is necessary; you just be able to just say
SetVisible(true);

[yiyix, 2016/09/12 17:31:24]

Done.

+    SetVisible(show_icon);
+  } else {
+    if (is_default_view_) {
+      WmShell::Get()->AddShellObserver(this);
+      SetVisible(WmShell::Get()
+                     ->maximize_mode_controller()
+                     ->IsMaximizeModeWindowManagerEnabled());
+    }
   }
 }
 
@@ -143,11 +151,13 @@ void BrightnessView::SetBrightnessPercent(double percent) {
 }
 
 void BrightnessView::OnMaximizeModeStarted() {
-  SetVisible(true);
+  if (!MaterialDesignController::IsSystemTrayMenuMaterial())
+    SetVisible(true);
 }
 
 void BrightnessView::OnMaximizeModeEnded() {
-  SetVisible(false);
+  if (!MaterialDesignController::IsSystemTrayMenuMaterial())
+    SetVisible(false);
 }
 
 void BrightnessView::OnBoundsChanged(const gfx::Rect& old_bounds) {