Add notification mechanism when BrowserActionButton's icon has been updated.

chrome/browser/ui/views/toolbar/browser_action_view.cc

Index: chrome/browser/ui/views/toolbar/browser_action_view.cc
diff --git a/chrome/browser/ui/views/toolbar/browser_action_view.cc b/chrome/browser/ui/views/toolbar/browser_action_view.cc
index 780e8c365efc650fa5fb270f81e98e1f88e85532..ddd873449441778107023a219cb08937df954fd5 100644
--- a/chrome/browser/ui/views/toolbar/browser_action_view.cc
+++ b/chrome/browser/ui/views/toolbar/browser_action_view.cc
@@ -115,6 +115,7 @@ BrowserActionButton::BrowserActionButton(const Extension* extension,
                                          BrowserActionView::Delegate* delegate)
     : MenuButton(this, base::string16(), NULL, false),
       browser_(browser),
+      icon_observer_(NULL),

[Finnur, 2014/02/10 11:20:57]

Move this line down one to avoid compile error seen on Linux try bot.

       browser_action_(
           extensions::ExtensionActionManager::Get(browser->profile())->
           GetBrowserAction(*extension)),
@@ -311,6 +312,15 @@ void BrowserActionButton::Observe(int type,
 
 void BrowserActionButton::OnIconUpdated() {
   UpdateState();
+  if (icon_observer_) {
+    int tab_id = delegate_->GetCurrentTabId();
+    gfx::Size spacing(0, ToolbarView::kVertSpacing);
+    gfx::ImageSkia icon = *icon_factory_.GetIcon(tab_id).ToImageSkia();
+    if (!IsEnabled(tab_id))
+      icon = gfx::ImageSkiaOperations::CreateTransparentImage(icon, .25);

[Finnur, 2014/02/10 10:41:41]

This is copied almost verbatim from GetIconWithBadge, but needs to be kept in
sync. Can you instead extract this into a helper function that both call? Have
it take for example a |tab_id| and an |icon_factory| as params.

+    icon_observer_->OnIconUpdated(
+        browser_action_->GetIconWithBadge(icon, tab_id, spacing));
+  }
 }
 
 bool BrowserActionButton::Activate() {