Improve tab-closability of right-most tab.

chrome/browser/cocoa/tab_strip_controller.mm

Index: chrome/browser/cocoa/tab_strip_controller.mm
diff --git a/chrome/browser/cocoa/tab_strip_controller.mm b/chrome/browser/cocoa/tab_strip_controller.mm
index 8c47c8e6e3dcb2a075f8a9e0d5175e72d3e1238f..9b4ec081b1703c792b25aea1e32f9cacf7a373a4 100644
--- a/chrome/browser/cocoa/tab_strip_controller.mm
+++ b/chrome/browser/cocoa/tab_strip_controller.mm
@@ -288,11 +288,19 @@ static const float kIndentLeavingSpaceForControls = 64.0;
     if (contents)
       UserMetrics::RecordAction(L"CloseTab_Mouse", contents->profile());
     if ([self numberOfTabViews] > 1) {
-      // Limit the width available for laying out tabs so that tabs are not
-      // resized until a later time (when the mouse leaves the tab strip).
-      // TODO(pinkerton): re-visit when handling tab overflow.
-      NSView* penultimateTab = [self viewAtIndex:[tabArray_ count] - 2];
-      availableResizeWidth_ = NSMaxX([penultimateTab frame]);
+      if (static_cast<size_t>(index) != [tabArray_ count] - 1) {

[pink (ping after 24hrs), 2009/09/16 14:37:16]

i'd reverse the if/else cases here. check for the rightmost tab in the if, and
the else can be the normal case.

+        // Limit the width available for laying out tabs so that tabs are not
+        // resized until a later time (when the mouse leaves the tab strip).
+        // TODO(pinkerton): re-visit when handling tab overflow.
+        NSView* penultimateTab = [self viewAtIndex:[tabArray_ count] - 2];
+        availableResizeWidth_ = NSMaxX([penultimateTab frame]);
+      } else {
+        // If the rightmost tab is closed, change the available width so that
+        // another tab's close button lands below the cursor (assuming the tabs
+        // are currently below their maximum width and can grow).
+        NSView* lastTab = [self viewAtIndex:[tabArray_ count] - 1];
+        availableResizeWidth_ = NSMaxX([lastTab frame]);
+      }
       tabModel_->CloseTabContentsAt(index);
     } else {
       // Use the standard window close if this is the last tab