Rejigger ThemeService: move exposure of ThemeProvider interface to a

chrome/browser/themes/theme_service_mac.mm

Index: chrome/browser/themes/theme_service_mac.mm
diff --git a/chrome/browser/themes/theme_service_mac.mm b/chrome/browser/themes/theme_service_mac.mm
index 1b9a5410caf44136215ba394fb9aaf242b4aad31..f5a96a9ec025965dacb8935ee48f533916edddf3 100644
--- a/chrome/browser/themes/theme_service_mac.mm
+++ b/chrome/browser/themes/theme_service_mac.mm
@@ -286,3 +286,28 @@ void ThemeService::FreePlatformCaches() {
   }
   nsgradient_cache_.clear();
 }
+
+bool ThemeService::BrowserThemeProvider::UsingSystemTheme() const {
+  return theme_service_->UsingSystemTheme();
+}
+
+NSImage* ThemeService::BrowserThemeProvider::GetNSImageNamed(int id) const {
+  return theme_service_->GetNSImageNamed(id);
+}
+
+NSColor* ThemeService::BrowserThemeProvider::GetNSImageColorNamed(
+    int id) const {
+  return theme_service_->GetNSImageColorNamed(id);
+}
+
+NSColor* ThemeService::BrowserThemeProvider::GetNSColor(int id) const {
+  return theme_service_->GetNSColor(id);
+}
+
+NSColor* ThemeService::BrowserThemeProvider::GetNSColorTint(int id) const {
+  return theme_service_->GetNSColorTint(id);
+}
+
+NSGradient* ThemeService::BrowserThemeProvider::GetNSGradient(int id) const {
+  return theme_service_->GetNSGradient(id);
+}