Render the tab close button as a vector-based icon.

chrome/browser/ui/views/tabs/media_indicator_button.cc

Index: chrome/browser/ui/views/tabs/media_indicator_button.cc
diff --git a/chrome/browser/ui/views/tabs/media_indicator_button.cc b/chrome/browser/ui/views/tabs/media_indicator_button.cc
index 881a12446d212a76d7293745bb538f789e710869..d2c2d9cdbfd6777bbe68ab4ae55102598c035706 100644
--- a/chrome/browser/ui/views/tabs/media_indicator_button.cc
+++ b/chrome/browser/ui/views/tabs/media_indicator_button.cc
@@ -71,18 +71,8 @@ void MediaIndicatorButton::TransitionToMediaState(TabMediaState next_state) {
   if (next_state == media_state_)
     return;
 
-  if (next_state != TAB_MEDIA_STATE_NONE) {
-    ui::ThemeProvider* tp = GetThemeProvider();
-    gfx::ImageSkia indicator_image =
-        chrome::GetTabMediaIndicatorImage(next_state, tp).AsImageSkia();
-    SetImage(views::CustomButton::STATE_NORMAL, &indicator_image);
-    SetImage(views::CustomButton::STATE_DISABLED, &indicator_image);
-    gfx::ImageSkia affordance_image =
-        chrome::GetTabMediaIndicatorAffordanceImage(next_state, tp)
-            .AsImageSkia();
-    SetImage(views::CustomButton::STATE_HOVERED, &affordance_image);
-    SetImage(views::CustomButton::STATE_PRESSED, &affordance_image);
-  }
+  if (next_state != TAB_MEDIA_STATE_NONE)
+    ResetImages(next_state);
 
   if ((media_state_ == TAB_MEDIA_STATE_AUDIO_PLAYING &&
        next_state == TAB_MEDIA_STATE_AUDIO_MUTING) ||
@@ -138,6 +128,12 @@ void MediaIndicatorButton::UpdateEnabledForMuteToggle() {
   SetEnabled(enable);
 }
 
+void MediaIndicatorButton::OnParentTabButtonColorChanged() {
+  if ((media_state_ == TAB_MEDIA_STATE_AUDIO_PLAYING) ||

[Evan Stade, 2015/09/23 18:16:35]

nit: imo there are more parens than necessary here

[Peter Kasting, 2015/09/23 20:44:13]

Yeah, this is an area where Chromium doesn't have a consistent style.  Should
non-unary subexprs be parenthesized always, never, or sometimes?  My personal
style is "always", but the rest of this file seems to go more with "never". 
Changed to match the file style better.

+      (media_state_ == TAB_MEDIA_STATE_AUDIO_MUTING))
+    ResetImages(media_state_);
+}
+
 const char* MediaIndicatorButton::GetClassName() const {
   return kViewClassName;
 }
@@ -245,3 +241,15 @@ Tab* MediaIndicatorButton::GetTab() const {
   DCHECK_EQ(static_cast<views::View*>(parent_tab_), parent());
   return parent_tab_;
 }
+
+void MediaIndicatorButton::ResetImages(TabMediaState state) {
+  SkColor color = parent_tab_->button_color();
+  gfx::ImageSkia indicator_image =
+      chrome::GetTabMediaIndicatorImage(state, color).AsImageSkia();
+  SetImage(views::CustomButton::STATE_NORMAL, &indicator_image);
+  SetImage(views::CustomButton::STATE_DISABLED, &indicator_image);
+  gfx::ImageSkia affordance_image =
+      chrome::GetTabMediaIndicatorAffordanceImage(state, color).AsImageSkia();
+  SetImage(views::CustomButton::STATE_HOVERED, &affordance_image);
+  SetImage(views::CustomButton::STATE_PRESSED, &affordance_image);
+}