Mac: Make it easier for views to correctly draw with a theme.

chrome/browser/ui/cocoa/floating_bar_backing_view.mm

Index: chrome/browser/ui/cocoa/floating_bar_backing_view.mm
diff --git a/chrome/browser/ui/cocoa/floating_bar_backing_view.mm b/chrome/browser/ui/cocoa/floating_bar_backing_view.mm
index 8e5494861ef6c616443dc096b0b495bd21237d70..96a5fff75812c0a480214509a2e6d37b89c3a39b 100644
--- a/chrome/browser/ui/cocoa/floating_bar_backing_view.mm
+++ b/chrome/browser/ui/cocoa/floating_bar_backing_view.mm
@@ -45,4 +45,14 @@
     ui::WindowTitlebarReceivedDoubleClick([self window], self);
 }
 
+// ThemedWindowDrawing implementation.
+
+- (void)windowDidChangeTheme {
+  [self setNeedsDisplay:YES];
+}
+
+- (void)windowDidChangeActive {
+  [self setNeedsDisplay:YES];
+}
+
 @end  // @implementation FloatingBarBackingView