Implement off-screen rendering support using delegated rendering (issue #1257).

This implementation supports both GPU compositing and software compositing (used when GPU is not supported or when passing `--disable-gpu --disable-gpu-compositing` command-line flags). GPU-accelerated features (WebGL and 3D CSS) that did not work with the previous off-screen rendering implementation do work with this implementation when GPU support is available.

Rendering now operates on a per-frame basis. The frame rate is configurable via CefBrowserSettings.windowless_frame_rate up to a maximum of 60fps (potentially limited by how fast the system can generate new frames). CEF generates a bitmap from the compositor backing and passes it to CefRenderHandler::OnPaint.

The previous CefRenderHandler/CefBrowserHost API for off-screen rendering has been restored mostly as-is with some minor changes:

- CefBrowserHost::Invalidate no longer accepts a CefRect region argument. Instead of invalidating a specific region it now triggers generation of a new frame.
- The |dirtyRects| argument to CefRenderHandler::OnPaint will now always be a single CefRect representing the whole view (frame) size. Previously, invalidated regions were listed separately.
- Linux: CefBrowserHost::SendKeyEvent now expects X11 event information instead of GTK event information. See cefclient for an example of converting GTK events to the necessary format.
- Sizes passed to the CefRenderHandler OnPaint and OnPopupSize methods are now already DPI scaled. Previously, the client had to perform DPI scaling.
- Includes drag&drop implementation from issue #1032.
- Includes unit test fixes from issue #1245.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1751 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

libcef_dll/ctocpp/render_handler_ctocpp.h

@@ -0,0 +1,63 @@
+// Copyright (c) 2014 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.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool. If making changes by
+// hand only do so within the body of existing method and function
+// implementations. See the translator.README.txt file in the tools directory
+// for more information.
+//
+
+#ifndef CEF_LIBCEF_DLL_CTOCPP_RENDER_HANDLER_CTOCPP_H_
+#define CEF_LIBCEF_DLL_CTOCPP_RENDER_HANDLER_CTOCPP_H_
+#pragma once
+
+#ifndef BUILDING_CEF_SHARED
+#pragma message("Warning: "__FILE__" may be accessed DLL-side only")
+#else  // BUILDING_CEF_SHARED
+
+#include "include/cef_render_handler.h"
+#include "include/capi/cef_render_handler_capi.h"
+#include "libcef_dll/ctocpp/ctocpp.h"
+
+// Wrap a C structure with a C++ class.
+// This class may be instantiated and accessed DLL-side only.
+class CefRenderHandlerCToCpp
+    : public CefCToCpp<CefRenderHandlerCToCpp, CefRenderHandler,
+        cef_render_handler_t> {
+ public:
+  explicit CefRenderHandlerCToCpp(cef_render_handler_t* str)
+      : CefCToCpp<CefRenderHandlerCToCpp, CefRenderHandler,
+          cef_render_handler_t>(str) {}
+  virtual ~CefRenderHandlerCToCpp() {}
+
+  // CefRenderHandler methods
+  virtual bool GetRootScreenRect(CefRefPtr<CefBrowser> browser,
+      CefRect& rect) OVERRIDE;
+  virtual bool GetViewRect(CefRefPtr<CefBrowser> browser,
+      CefRect& rect) OVERRIDE;
+  virtual bool GetScreenPoint(CefRefPtr<CefBrowser> browser, int viewX,
+      int viewY, int& screenX, int& screenY) OVERRIDE;
+  virtual bool GetScreenInfo(CefRefPtr<CefBrowser> browser,
+      CefScreenInfo& screen_info) OVERRIDE;
+  virtual void OnPopupShow(CefRefPtr<CefBrowser> browser, bool show) OVERRIDE;
+  virtual void OnPopupSize(CefRefPtr<CefBrowser> browser,
+      const CefRect& rect) OVERRIDE;
+  virtual void OnPaint(CefRefPtr<CefBrowser> browser, PaintElementType type,
+      const RectList& dirtyRects, const void* buffer, int width,
+      int height) OVERRIDE;
+  virtual void OnCursorChange(CefRefPtr<CefBrowser> browser,
+      CefCursorHandle cursor) OVERRIDE;
+  virtual bool StartDragging(CefRefPtr<CefBrowser> browser,
+      CefRefPtr<CefDragData> drag_data, DragOperationsMask allowed_ops, int x,
+      int y) OVERRIDE;
+  virtual void UpdateDragCursor(CefRefPtr<CefBrowser> browser,
+      DragOperation operation) OVERRIDE;
+  virtual void OnScrollOffsetChanged(CefRefPtr<CefBrowser> browser) OVERRIDE;
+};
+
+#endif  // BUILDING_CEF_SHARED
+#endif  // CEF_LIBCEF_DLL_CTOCPP_RENDER_HANDLER_CTOCPP_H_
+