Implement tooltips for the Go/Stop button in Linux.

chrome/browser/gtk/go_button_gtk_unittest.cc

 // Copyright (c) 2009 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/gtk/go_button_gtk.h"
 #include "base/task.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class GoButtonGtkPeer {
  public:
@@ skipping 24 matching lines @@
   }
 
  private:
   GoButtonGtk* const go_;
 };
 
 namespace {
 
 class GoButtonGtkTest : public testing::Test {
  protected:
-  GoButtonGtkTest() : go_(NULL), peer_(&go_) { }
+  GoButtonGtkTest() : go_(NULL, NULL), peer_(&go_) { }
 
  protected:
   GoButtonGtk go_;
   GoButtonGtkPeer peer_;
 };
 
 TEST_F(GoButtonGtkTest, ChangeModeGo) {
   go_.ChangeMode(GoButtonGtk::MODE_GO);
   EXPECT_EQ(GoButtonGtk::MODE_GO, peer_.intended_mode());
   EXPECT_EQ(GoButtonGtk::MODE_GO, peer_.visible_mode());
@@ skipping 65 matching lines @@
 }
 
 TEST_F(GoButtonGtkTest, OnClickedStop) {
   peer_.set_visible_mode(GoButtonGtk::MODE_STOP);
   EXPECT_TRUE(peer_.OnClicked());
   EXPECT_EQ(GoButtonGtk::MODE_GO, peer_.visible_mode());
   EXPECT_EQ(GoButtonGtk::MODE_GO, peer_.intended_mode());
 }
 
 }  // namespace