MacViews: Implement Tooltips

ui/views/cocoa/tooltip_manager_mac.h

+// Copyright 2015 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.
+
+#ifndef UI_VIEWS_COCOA_TOOLTOP_MANAGER_MAC_H_
+#define UI_VIEWS_COCOA_TOOLTOP_MANAGER_MAC_H_
+
+#include "base/macros.h"
+#include "ui/views/widget/tooltip_manager.h"
+
+namespace views {
+class BridgedNativeWidget;
+
+// Manages native Cocoa tooltips for the given BridgedNativeWidget.
+class TooltipManagerMac : public TooltipManager {
+ public:
+  explicit TooltipManagerMac(BridgedNativeWidget* widget);
+  ~TooltipManagerMac() override;
+
+  // TooltipManager:
+  int GetMaxWidth(const gfx::Point& location,
+                  gfx::NativeView context) const override;
+  const gfx::FontList& GetFontList() const override;
+  void UpdateTooltip() override;
+  void TooltipTextChanged(View* view) override;
+
+ private:
+  BridgedNativeWidget* widget_;  // Weak. Owns this.
+
+  DISALLOW_COPY_AND_ASSIGN(TooltipManagerMac);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_COCOA_TOOLTOP_MANAGER_MAC_H_