Prevent bookmarks bar toggling from decreasing window height to 0.

chrome/browser/ui/cocoa/browser_window_controller.mm

 // Copyright 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.
 
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 
 #include <cmath>
 #include <numeric>
 
 #include "base/command_line.h"
@@ skipping 820 matching lines @@
 - (BOOL)adjustWindowHeightBy:(CGFloat)deltaH {
   // By not adjusting the window height when initializing, we can ensure that
   // the window opens with the same size that was saved on close.
   if (initializing_ || [self isInAnyFullscreenMode] || deltaH == 0)
     return NO;
 
   NSWindow* window = [self window];
   NSRect windowFrame = [window frame];
   NSRect workarea = [[window screen] visibleFrame];
 
+  // Prevent the window from growing smaller than its minimum height:
+  // http://crbug.com/230400 .
+  if (deltaH < 0) {
+    CGFloat minWindowHeight = [window minSize].height;
+    if (windowFrame.size.height + deltaH < minWindowHeight) {
+      // |deltaH| + |windowFrame.size.height| = |minWindowHeight|.
+      deltaH = minWindowHeight - windowFrame.size.height;
+    }
+    if (deltaH == 0) {
+      return NO;
+    }
+  }
+
   // If the window is not already fully in the workarea, do not adjust its frame
   // at all.
   if (!NSContainsRect(workarea, windowFrame))
     return NO;
 
   // Record the position of the top/bottom of the window, so we can easily check
   // whether we grew the window upwards/downwards.
   CGFloat oldWindowMaxY = NSMaxY(windowFrame);
   CGFloat oldWindowMinY = NSMinY(windowFrame);
 
@@ skipping 1355 matching lines @@
 
 - (BOOL)supportsBookmarkBar {
   return [self supportsWindowFeature:Browser::FEATURE_BOOKMARKBAR];
 }
 
 - (BOOL)isTabbedWindow {
   return browser_->is_type_tabbed();
 }
 
 @end  // @implementation BrowserWindowController(WindowType)