- Factor platform-specific code out of CefBrowserHostImpl (issue #1749).

- Introduce native/ and osr/ folders for native (non-platform-agnostic) and
    osr (windowless) code respectively.
  - Introduce CefBrowserPlatformDelegate for abstracting platform-specific
    implementations of browser host functionality.
  - Move dialog and menu code to separate manager and platform-specific runner
    implementations exposed via CefBrowserPlatformDelegate.
  - Standardize focus-handling behavior between windowed and windowless
    implementations. CefFocusHandler::OnSetFocus() will now also be called for
    osr focus changes.
- Support multiple simultaneous popups (issue #1289).

libcef/browser/native/browser_platform_delegate_native.h

@@ -0,0 +1,48 @@
+// Copyright 2015 The Chromium Embedded Framework 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 CEF_LIBCEF_BROWSER_NATIVE_BROWSER_PLATFORM_DELEGATE_NATIVE_H_
+#define CEF_LIBCEF_BROWSER_NATIVE_BROWSER_PLATFORM_DELEGATE_NATIVE_H_
+
+#include "libcef/browser/browser_platform_delegate.h"
+
+// Base implementation of native browser functionality.
+class CefBrowserPlatformDelegateNative : public CefBrowserPlatformDelegate {
+ public:
+  // Used by the windowless implementation to override specific functionality
+  // when delegating to the native implementation.
+  class WindowlessHandler {
+   public:
+    // Returns the parent window handle.
+    virtual CefWindowHandle GetParentWindowHandle() const = 0;
+
+    // Convert from view coordinates to screen coordinates.
+    virtual gfx::Point GetParentScreenPoint(const gfx::Point& view) const = 0;
+
+   protected:
+    virtual ~WindowlessHandler() {}
+  };
+
+  // CefBrowserPlatformDelegate methods:
+  void WasResized() override;
+  void SendKeyEvent(const content::NativeWebKeyboardEvent& event) override;
+  void SendMouseEvent(const blink::WebMouseEvent& event) override;
+  void SendMouseWheelEvent(const blink::WebMouseWheelEvent& event) override;
+  bool IsWindowless() const override;
+
+  const CefWindowInfo& window_info() const { return window_info_; }
+
+  void set_windowless_handler(WindowlessHandler* handler) {
+    windowless_handler_ = handler;
+  }
+
+ protected:
+  explicit CefBrowserPlatformDelegateNative(const CefWindowInfo& window_info);
+
+  CefWindowInfo window_info_;
+
+  WindowlessHandler* windowless_handler_;  // Not owned by this object.
+};
+
+#endif  // CEF_LIBCEF_BROWSER_NATIVE_BROWSER_PLATFORM_DELEGATE_NATIVE_H_