Draw background of Linux extension toolstrips.

chrome/browser/gtk/extension_shelf_gtk.cc

Index: chrome/browser/gtk/extension_shelf_gtk.cc
diff --git a/chrome/browser/gtk/extension_shelf_gtk.cc b/chrome/browser/gtk/extension_shelf_gtk.cc
index 121f77dade6f9a9f1ca2f92b29f40b8b87101255..0383dcc7ffd1117df2e0f37d6a4b9a79064c3f01 100644
--- a/chrome/browser/gtk/extension_shelf_gtk.cc
+++ b/chrome/browser/gtk/extension_shelf_gtk.cc
@@ -37,6 +37,10 @@ class ExtensionShelfGtk::Toolstrip {
   void AddToolstripToBox(GtkWidget* box);
   void RemoveToolstripFromBox(GtkWidget* box);
 
+  void SetBackground(const SkBitmap& background) {
+    host_->view()->SetBackground(background);
+  }
+
  private:
   void Init();
 
@@ -93,7 +97,9 @@ void ExtensionShelfGtk::Hide() {
 
 void ExtensionShelfGtk::ToolstripInsertedAt(ExtensionHost* host,
                                             int index) {
+  InitBackground();
   Toolstrip* toolstrip = new Toolstrip(host);
+  toolstrip->SetBackground(*background_.get());
   toolstrip->AddToolstripToBox(shelf_hbox_);
   toolstrips_.insert(toolstrip);
   model_->SetToolstripDataAt(index, toolstrip);
@@ -188,6 +194,17 @@ void ExtensionShelfGtk::Init(Profile* profile) {
   model_->AddObserver(this);
 }
 
+void ExtensionShelfGtk::InitBackground() {
+  if (background_.get())
+    return;
+  background_.reset(new SkBitmap);
+  background_->setConfig(SkBitmap::kARGB_8888_Config, 3, 3);
+  background_->allocPixels();
+  background_->eraseRGB(kBackgroundColor.red >> 8,
+                        kBackgroundColor.green >> 8,
+                        kBackgroundColor.blue >> 8);
+}
+
 void ExtensionShelfGtk::AdjustHeight() {
   if (model_->empty() || toolstrips_.empty()) {
     // It's possible that |model_| is not empty, but |toolstrips_| are empty