Attempt 2 at:

chrome/browser/views/tabs/tab.cc

 // Copyright (c) 2010 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 "chrome/browser/views/tabs/tab.h"
 
 #include <limits>
 
 #include "app/multi_animation.h"
 #include "app/resource_bundle.h"
 #include "app/slide_animation.h"
 #include "app/throb_animation.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_theme_provider.h"
 #include "chrome/browser/defaults.h"
 #include "gfx/canvas.h"
 #include "gfx/favicon_size.h"
 #include "gfx/font.h"
 #include "gfx/path.h"
 #include "gfx/skbitmap_operations.h"
 #include "grit/app_resources.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "third_party/skia/include/effects/SkGradientShader.h"
 #include "views/controls/button/image_button.h"
+#include "views/widget/root_view.h"
 #include "views/widget/tooltip_manager.h"
 #include "views/widget/widget.h"
 #include "views/window/non_client_view.h"
 #include "views/window/window.h"
 
 static const int kLeftPadding = 16;
 static const int kTopPadding = 6;
 static const int kRightPadding = 15;
 static const int kBottomPadding = 5;
 static const int kDropShadowHeight = 2;
@@ skipping 62 matching lines @@
 
 }  // namespace
 
 // static
 const char Tab::kViewClassName[] = "browser/tabs/Tab";
 
 ////////////////////////////////////////////////////////////////////////////////
 // Tab, public:
 
 Tab::Tab(TabController* controller)
-    : BaseTab(controller),
+    : BaseTab(controller, true),
       showing_icon_(false),
       showing_close_button_(false),
       close_button_color_(NULL),
       render_as_new_tab_(false),
       render_unselected_(false),
       alpha_(1) {
   InitTabResources();
 }
 
 Tab::~Tab() {
@@ skipping 106 matching lines @@
           BrowserThemeProvider::COLOR_TAB_TEXT :
           BrowserThemeProvider::COLOR_BACKGROUND_TAB_TEXT);
 
   if (!data().mini || width() > kMiniTabRendererAsNormalTabWidth)
     PaintTitle(canvas, title_color);
 
   if (show_icon)
     PaintIcon(canvas);
 
   // If the close button color has changed, generate a new one.
-  if (!close_button_color_ || title_color != close_button_color_) {
-    close_button_color_ = title_color;
-    ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-    close_button()->SetBackground(close_button_color_,
-        rb.GetBitmapNamed(IDR_TAB_CLOSE),
-        rb.GetBitmapNamed(IDR_TAB_CLOSE_MASK));
-  }
+  SetCloseButtonColor(title_color);
 }
 
 void Tab::Layout() {
   gfx::Rect lb = GetLocalBounds(false);
   if (lb.IsEmpty())
     return;
   lb.Inset(kLeftPadding, kTopPadding, kRightPadding, kBottomPadding);
 
   // The height of the content of the Tab is the largest of the favicon,
   // the title text and the close button graphic.
@@ skipping 27 matching lines @@
             (ideal_x - favicon_bounds_.x()));
         favicon_bounds_.set_x(x);
       }
     }
   } else {
     favicon_bounds_.SetRect(lb.x(), lb.y(), 0, 0);
   }
 
   // Size the Close button.
   showing_close_button_ = ShouldShowCloseBox();
+  gfx::Insets near_insets;
   if (showing_close_button_) {
     int close_button_top =
         kTopPadding + kCloseButtonVertFuzz +
         (content_height - close_button_height()) / 2;
     // If the ratio of the close button size to tab width exceeds the maximum.
     close_button()->SetBounds(lb.width() + kCloseButtonHorzFuzz,
                               close_button_top, close_button_width(),
                               close_button_height());
     close_button()->SetVisible(true);
+    int avail_width = width() - close_button()->bounds().right();
+    if (avail_width > 0) {
+      View* root = GetRootView();
+      if (root) {  // Root is NULL when dragging.
+        // Enable mouse near events for the region from the top of the browser
+        // to the bottom of the tab.
+        gfx::Point loc;
+        ConvertPointToView(close_button(), GetRootView(), &loc);
+        near_insets.Set(loc.y(), close_button()->x(),
+                        height() - close_button()->bounds().bottom(),
+                        avail_width);
+      }
+    }
   } else {
     close_button()->SetBounds(0, 0, 0, 0);
     close_button()->SetVisible(false);
   }
+  close_button()->RegisterForMouseNearEvents(near_insets);
 
   int title_left = favicon_bounds_.right() + kFavIconTitleSpacing;
   int title_top = kTopPadding + (content_height - font_height()) / 2;
   // Size the Title text to fill the remaining space.
   if (!data().mini || width() >= kMiniTabRendererAsNormalTabWidth) {
     // If the user has big fonts, the title will appear rendered too far down
     // on the y-axis if we use the regular top padding, so we need to adjust it
     // so that the text appears centered.
     gfx::Size minimum_size = GetMinimumUnselectedSize();
     int text_height = title_top + font_height() + kBottomPadding;
@@ skipping 380 matching lines @@
   tab_inactive_nano.image_l = rb.GetBitmapNamed(IDR_TAB_INACTIVE_NANO_LEFT);
   tab_inactive_nano.image_c = rb.GetBitmapNamed(IDR_TAB_INACTIVE_NANO_CENTER);
   tab_inactive_nano.image_r = rb.GetBitmapNamed(IDR_TAB_INACTIVE_NANO_RIGHT);
   tab_inactive_nano.l_width = tab_inactive_nano.image_l->width();
   tab_inactive_nano.r_width = tab_inactive_nano.image_r->width();
   tab_inactive_nano.y_offset = kNanoTabDiffHeight;
 
   new_tab_mask = rb.GetBitmapNamed(IDR_TAB_ALPHA_NEW_TAB);
   new_tab_shadow = rb.GetBitmapNamed(IDR_TAB_NEW_TAB_SHADOW);
 }