Fix crash in touch layout code. Without this can end up indexing into

chrome/browser/ui/views/tabs/touch_tab_strip_layout_unittest.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 "chrome/browser/ui/views/tabs/touch_tab_strip_layout.h"
 
 #include <string>
 
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
@@ skipping 305 matching lines @@
         " at " << i;
   }
 }
 
 // Assertions for SetWidth().
 TEST_F(TouchTabStripLayoutTest, SetWidth) {
   struct TestData {
     CommonTestData common_data;
     int new_width;
   } test_data[] = {
+    // Verifies a bug in AdjustTrailingStackedTabs().
+    { { 0, 103, 100, -10, 2, 0, 0, "", "0 2"}, 102 },
+
     { { 8, 250, 100, -10, 2, 2, 2, "0 4 8 98 148 150", "0 4 8 98 160 250"},
       350 },
     { { 8, 250, 100, -10, 2, 2, 2, "0 4 8 98 148 150", "0 4 8 96 98 100"},
       200 },
 
     { { 0, 250, 100, -10, 2, 0, 2, "0 40 90 120 150", "0 40 90 98 100"}, 200 },
     { { 0, 250, 100, -10, 2, 0, 2, "0 2 60 150", "0 2 60 100"}, 200 },
     { { 0, 250, 100, -10, 2, 0, 2, "0 40 120 150", "0 40 98 100"}, 200 },
 
     { { 0, 200, 100, -10, 2, 0, 2, "0 2 10 100", "0 2 60 150"}, 250 },
@@ skipping 31 matching lines @@
 // Makes sure don't crash when resized and only one tab.
 TEST_F(TouchTabStripLayoutTest, EmptyTest) {
   TouchTabStripLayout layout(gfx::Size(160, 10), -27, 6, 4, &view_model_);
   PrepareChildViews(1);
   layout.AddTab(0, TouchTabStripLayout::kAddTypeActive, 0);
   layout.SetWidth(100);
   layout.SetWidth(50);
   layout.SetWidth(0);
   layout.SetWidth(500);
 }