Fix SizeLabelToMinWidth() function such that no unnecessary space

chrome/browser/ui/views/download/download_item_view_unittest.cc

+// Copyright 2016 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/download/download_item_view.h"
+
+#include "base/strings/utf_string_conversions.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/test/views_test_base.h"
+
+using DownloadItemViewDangerousDownloadLabelTest = views::ViewsTestBase;
+
+TEST_F(DownloadItemViewDangerousDownloadLabelTest, AdjustTextAndGetSize) {
+  // For very short label that can fit in a single line, no need to do any
+  // adjustment, return it directly.
+  base::string16 label_text = base::ASCIIToUTF16("short");
+  views::Label label(label_text);
+  label.SetMultiLine(true);
+  DownloadItemView::AdjustTextAndGetSize(&label);
+  EXPECT_EQ(label_text, label.text());
+
+  // When we have multiple linebreaks that result in the same minimum width, we
+  // should place as much text as possible on the first line.
+  label_text = base::ASCIIToUTF16(
+      "aaaa aaaa aaaa aaaa aaaa aaaa bb aaaa aaaa aaaa aaaa aaaa aaaa");
+  base::string16 expected_text = base::ASCIIToUTF16(
+      "aaaa aaaa aaaa aaaa aaaa aaaa bb\n"
+      "aaaa aaaa aaaa aaaa aaaa aaaa");
+  label.SetText(label_text);
+  DownloadItemView::AdjustTextAndGetSize(&label);
+  EXPECT_EQ(expected_text, label.text());
+
+  // If the label is a single word and extremely long, we should not break it
+  // into 2 lines.
+  label_text = base::ASCIIToUTF16(
+      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
+  label.SetText(label_text);
+  DownloadItemView::AdjustTextAndGetSize(&label);
+  EXPECT_EQ(label_text, label.text());
+}