Adds scroll buttons to side tabs so that you can get to all the tabs.

chrome/browser/ui/views/tabs/side_tab_strip.h

Index: chrome/browser/ui/views/tabs/side_tab_strip.h
diff --git a/chrome/browser/ui/views/tabs/side_tab_strip.h b/chrome/browser/ui/views/tabs/side_tab_strip.h
index 9c4038261a10e7e6311a887409e869e437a01b79..54365ada19400c1ef89098cbf56149214d1a7880 100644
--- a/chrome/browser/ui/views/tabs/side_tab_strip.h
+++ b/chrome/browser/ui/views/tabs/side_tab_strip.h
@@ -7,10 +7,11 @@
 #pragma once
 
 #include "chrome/browser/ui/views/tabs/base_tab_strip.h"
+#include "views/controls/button/button.h"
 
 struct TabRendererData;
 
-class SideTabStrip : public BaseTabStrip {
+class SideTabStrip : public BaseTabStrip, public views::ButtonListener {
  public:
   // The tabs are inset by this much along all axis.
   static const int kTabStripInset;
@@ -33,6 +34,12 @@ class SideTabStrip : public BaseTabStrip {
   // views::View overrides:
   virtual gfx::Size GetPreferredSize() OVERRIDE;
   virtual void PaintChildren(gfx::Canvas* canvas) OVERRIDE;
+  virtual views::View* GetEventHandlerForPoint(
+      const gfx::Point& point) OVERRIDE;
+
+  // views::ButtonListener overrides:
+  virtual void ButtonPressed(views::Button* sender,
+                             const views::Event& event) OVERRIDE;
 
  protected:
   // BaseTabStrip overrides:
@@ -51,13 +58,32 @@ class SideTabStrip : public BaseTabStrip {
       std::vector<gfx::Rect>* bounds) OVERRIDE;
   virtual int GetSizeNeededForTabs(const std::vector<BaseTab*>& tabs) OVERRIDE;
 
+  // views::View protected overrides:
+  virtual void OnBoundsChanged(const gfx::Rect& previous_bounds) OVERRIDE;
+
  private:
+  // Sets |first_tab_y_offset_|. This ensures |new_offset| is legal.
+  void SetFirstTabYOffset(int new_offset);
+
+  // Returns the max y offset.
+  int GetMaxOffset() const;
+
+  // Returns the max visible y-coordinate for tabs.
+  int GetMaxTabY() const;
+
+  // Make sure the tab at |tab_index| is visible.
+  void MakeTabVisible(int tab_index);
+
   // The "New Tab" button.
   views::View* newtab_button_;
 
   // Ideal bounds of the new tab button.
   gfx::Rect newtab_button_bounds_;
 
+  // Scroll buttons.
+  views::View* scroll_up_button_;
+  views::View* scroll_down_button_;
+
   // Separator between mini-tabs and the new tab button. The separator is
   // positioned above the visible area if there are no mini-tabs.
   views::View* separator_;
@@ -65,6 +91,14 @@ class SideTabStrip : public BaseTabStrip {
   // Bounds of the sepatator.
   gfx::Rect separator_bounds_;
 
+  // Offset the first tab (or new tab button) is positioned at. If the user has
+  // scrolled the tabs this is non-zero.
+  int first_tab_y_offset_;
+
+  // Height needed to display the tabs, separator and new tab button. Doesn't
+  // include any padding.
+  int ideal_height_;
+
   DISALLOW_COPY_AND_ASSIGN(SideTabStrip);
 };