Don't update media toolbar button icon when enabled state changes

Previously, MediaToolbarButton has different image for enabled states
on Mac. Please refer to https://chromium-review.googlesource.com/c/chromium/src/+/1815904.

But it's not true at this point, so we don't need this calls anymore.

This is prework for ToolbarButton refactoring

Bug: 1048901
Change-Id: Ife793fe1bc5093fe30cce4fcbd01bcff58799f43
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2275359Reviewed-by: Tommy Steimel <steimel@chromium.org>
Commit-Queue: Sang Woo Ko <sangwoo108@chromium.org>
Cr-Commit-Position: refs/heads/master@{#784282}

chrome/browser/ui/views/global_media_controls/media_toolbar_button_view.cc

@@ -105,10 +105,6 @@ void MediaToolbarButtonView::Hide() {
 void MediaToolbarButtonView::Enable() {
   SetEnabled(true);
 
-#if defined(OS_MACOSX)
-  UpdateIcon();
-#endif  // defined(OS_MACOSX)
-
   for (auto& observer : observers_)
     observer.OnMediaButtonEnabled();
 }
@@ -116,10 +112,6 @@ void MediaToolbarButtonView::Enable() {
 void MediaToolbarButtonView::Disable() {
   SetEnabled(false);
 
-#if defined(OS_MACOSX)
-  UpdateIcon();
-#endif  // defined(OS_MACOSX)
-
   // Inform observers. Since the promo controller cares about disabling, we need
   // to ensure that it's created.
   EnsurePromoController();
@@ -134,9 +126,6 @@ SkColor MediaToolbarButtonView::GetInkDropBaseColor() const {
 }
 
 void MediaToolbarButtonView::UpdateIcon() {
-  if (!GetWidget())
-    return;
-
   const bool touch_ui = ui::TouchUiController::Get()->touch_ui();
   const gfx::VectorIcon& icon =
       touch_ui ? kMediaToolbarButtonTouchIcon : kMediaToolbarButtonIcon;