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

include/cef_drag_data.h

@@ -39,6 +39,7 @@
 #pragma once
 
 #include "include/cef_base.h"
+#include "include/cef_stream.h"
 #include <vector>
 
 ///
@@ -48,6 +49,24 @@
 /*--cef(source=library)--*/
 class CefDragData : public virtual CefBase {
  public:
+  ///
+  // Create a new CefDragData object.
+  ///
+  /*--cef()--*/
+  static CefRefPtr<CefDragData> Create();
+
+  ///
+  // Returns a copy of the current object.
+  ///
+  /*--cef()--*/
+  virtual CefRefPtr<CefDragData> Clone() =0;
+
+  ///
+  // Returns true if this object is read-only.
+  ///
+  /*--cef()--*/
+  virtual bool IsReadOnly() =0;
+
   ///
   // Returns true if the drag data is a link.
   ///
@@ -109,12 +128,71 @@ class CefDragData : public virtual CefBase {
   /*--cef()--*/
   virtual CefString GetFileName() =0;
 
+  ///
+  // Write the contents of the file being dragged out of the web view into
+  // |writer|. Returns the number of bytes sent to |writer|. If |writer| is
+  // NULL this method will return the size of the file contents in bytes.
+  // Call GetFileName() to get a suggested name for the file.
+  ///
+  /*--cef(optional_param=writer)--*/
+  virtual size_t GetFileContents(CefRefPtr<CefStreamWriter> writer) =0;
+
   ///
   // Retrieve the list of file names that are being dragged into the browser
   // window.
   ///
   /*--cef()--*/
   virtual bool GetFileNames(std::vector<CefString>& names) =0;
+
+  ///
+  // Set the link URL that is being dragged.
+  ///
+  /*--cef(optional_param=url)--*/
+  virtual void SetLinkURL(const CefString& url) =0;
+
+  ///
+  // Set the title associated with the link being dragged.
+  ///
+  /*--cef(optional_param=title)--*/
+  virtual void SetLinkTitle(const CefString& title) =0;
+
+  ///
+  // Set the metadata associated with the link being dragged.
+  ///
+  /*--cef(optional_param=data)--*/
+  virtual void SetLinkMetadata(const CefString& data) =0;
+
+  ///
+  // Set the plain text fragment that is being dragged.
+  ///
+  /*--cef(optional_param=text)--*/
+  virtual void SetFragmentText(const CefString& text) =0;
+
+  ///
+  // Set the text/html fragment that is being dragged.
+  ///
+  /*--cef(optional_param=html)--*/
+  virtual void SetFragmentHtml(const CefString& html) =0;
+
+  ///
+  // Set the base URL that the fragment came from.
+  ///
+  /*--cef(optional_param=base_url)--*/
+  virtual void SetFragmentBaseURL(const CefString& base_url) =0;
+
+  ///
+  // Reset the file contents. You should do this before calling
+  // CefBrowserHost::DragTargetDragEnter as the web view does not allow us to
+  // drag in this kind of data.
+  ///
+  /*--cef()--*/
+  virtual void ResetFileContents() =0;
+
+  ///
+  // Add a file that is being dragged into the webview.
+  ///
+  /*--cef(optional_param=display_name)--*/
+  virtual void AddFile(const CefString& path, const CefString& display_name) =0;
 };
 
 #endif  // CEF_INCLUDE_CEF_DRAG_DATA_H_