(Views only) Add a gradient background to the tabstrip of the view tabbed pane implementation.

ui/views/controls/tabbed_pane/native_tabbed_pane_views.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/tabbed_pane/native_tabbed_pane_views.h"
 
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas.h"
@@ skipping 106 matching lines @@
   SkColor title_color_;
 
   DISALLOW_COPY_AND_ASSIGN(Tab);
 };
 
 class TabStrip : public View {
  public:
   explicit TabStrip(NativeTabbedPaneViews* owner)
       : owner_(owner),
         selected_tab_(NULL) {
+    const int kCount = 4;
+    // The gradient colors are derived from the tabbed panes used for the
+    // WebUI.
+    SkColor colors[] = {
+        SkColorSetRGB(0xff, 0xff, 0xff),
+        SkColorSetRGB(0xff, 0xff, 0xff),
+        SkColorSetRGB(0xfa, 0xfa, 0xfa),
+        SkColorSetRGB(0xf2, 0xf2, 0xf2)
+    };
+    // The relative positions of the gradient colors are derived from the
+    // tabbed panes used for the WebUI.
+    SkScalar pos[4] = {0.0f, 0.6f, 0.8f, 1.0f};
+    set_background(Background::CreateVerticalMultiColorGradientBackground(
+        colors, pos, kCount));
   }
   virtual ~TabStrip() {}
 
   void SelectTab(View* tab) {
     if (tab == selected_tab_)
       return;
     if (selected_tab_)
       static_cast<Tab*>(selected_tab_)->OnSelectedStateChanged(false);
     selected_tab_ = tab;
     static_cast<Tab*>(selected_tab_)->OnSelectedStateChanged(true);
@@ skipping 23 matching lines @@
   virtual void Layout() OVERRIDE {
     const int kTabOffset = 18;
     int x = kTabOffset;  // Layout tabs with an offset to the tabstrip border.
     for (int i = 0; i < child_count(); ++i) {
       gfx::Size ps = child_at(i)->GetPreferredSize();
       child_at(i)->SetBounds(x, 0, ps.width(), ps.height());
       x = child_at(i)->bounds().right();
     }
   }
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
+    OnPaintBackground(canvas);
+
+    // Draw the TabStrip border.
     SkPaint paint;
     paint.setColor(kTabBorderColor);
     paint.setStrokeWidth(kTabBorderThickness);
     SkScalar line_y = SkIntToScalar(height()) - kTabBorderThickness;
     SkScalar line_width = SkIntToScalar(width());
     canvas->sk_canvas()->drawLine(0, line_y, line_width, line_y, paint);
   }
 
  private:
   NativeTabbedPaneViews* owner_;
@@ skipping 222 matching lines @@
   if (tab_strip_->has_children())
     InitializeTabs();
 }
 
 void NativeTabbedPaneViews::InitializeTabs() {
   for (int i = 0; i < tab_strip_->child_count(); ++i)
     content_view_->AddChildView(Tab::GetContents(tab_strip_->child_at(i)));
 }
 
 }  // namespace views