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

tests/cefclient/client_handler.cpp

@@ -240,7 +240,7 @@ void ClientHandler::OnDownloadUpdated(
 
 bool ClientHandler::OnDragEnter(CefRefPtr<CefBrowser> browser,
                                 CefRefPtr<CefDragData> dragData,
-                                DragOperationsMask mask) {
+                                CefDragHandler::DragOperationsMask mask) {
   REQUIRE_UI_THREAD();
 
   // Forbid dragging of link URLs.
@@ -279,6 +279,22 @@ bool ClientHandler::OnPreKeyEvent(CefRefPtr<CefBrowser> browser,
   return false;
 }
 
+bool ClientHandler::OnBeforePopup(CefRefPtr<CefBrowser> browser,
+                                  CefRefPtr<CefFrame> frame,
+                                  const CefString& target_url,
+                                  const CefString& target_frame_name,
+                                  const CefPopupFeatures& popupFeatures,
+                                  CefWindowInfo& windowInfo,
+                                  CefRefPtr<CefClient>& client,
+                                  CefBrowserSettings& settings,
+                                  bool* no_javascript_access) {
+  if (browser->GetHost()->IsWindowRenderingDisabled()) {
+    // Cancel popups in off-screen rendering mode.
+    return true;
+  }
+  return false;
+}
+
 void ClientHandler::OnAfterCreated(CefRefPtr<CefBrowser> browser) {
   REQUIRE_UI_THREAD();
 
@@ -341,6 +357,11 @@ void ClientHandler::OnBeforeClose(CefRefPtr<CefBrowser> browser) {
   if (m_BrowserId == browser->GetIdentifier()) {
     // Free the browser pointer so that the browser can be destroyed
     m_Browser = NULL;
+
+    if (m_OSRHandler.get()) {
+      m_OSRHandler->OnBeforeClose(browser);
+      m_OSRHandler = NULL;
+    }
   } else if (browser->IsPopup()) {
     // Remove from the browser popup list.
     BrowserList::iterator bit = m_PopupBrowsers.begin();
@@ -491,6 +512,84 @@ void ClientHandler::OnRenderProcessTerminated(CefRefPtr<CefBrowser> browser,
   }
 }
 
+bool ClientHandler::GetRootScreenRect(CefRefPtr<CefBrowser> browser,
+    CefRect& rect) {
+  if (!m_OSRHandler.get())
+    return false;
+  return m_OSRHandler->GetRootScreenRect(browser, rect);
+}
+
+bool ClientHandler::GetViewRect(CefRefPtr<CefBrowser> browser, CefRect& rect) {
+  if (!m_OSRHandler.get())
+    return false;
+  return m_OSRHandler->GetViewRect(browser, rect);
+}
+
+bool ClientHandler::GetScreenPoint(CefRefPtr<CefBrowser> browser,
+                                   int viewX,
+                                   int viewY,
+                                   int& screenX,
+                                   int& screenY) {
+  if (!m_OSRHandler.get())
+    return false;
+  return m_OSRHandler->GetScreenPoint(browser, viewX, viewY, screenX, screenY);
+}
+
+bool ClientHandler::GetScreenInfo(CefRefPtr<CefBrowser> browser,
+                                  CefScreenInfo& screen_info) {
+  if (!m_OSRHandler.get())
+    return false;
+  return m_OSRHandler->GetScreenInfo(browser, screen_info);
+}
+
+void ClientHandler::OnPopupShow(CefRefPtr<CefBrowser> browser,
+                                bool show) {
+  if (!m_OSRHandler.get())
+    return;
+  return m_OSRHandler->OnPopupShow(browser, show);
+}
+
+void ClientHandler::OnPopupSize(CefRefPtr<CefBrowser> browser,
+                                const CefRect& rect) {
+  if (!m_OSRHandler.get())
+    return;
+  return m_OSRHandler->OnPopupSize(browser, rect);
+}
+
+void ClientHandler::OnPaint(CefRefPtr<CefBrowser> browser,
+                            PaintElementType type,
+                            const RectList& dirtyRects,
+                            const void* buffer,
+                            int width,
+                            int height) {
+  if (!m_OSRHandler.get())
+    return;
+  m_OSRHandler->OnPaint(browser, type, dirtyRects, buffer, width, height);
+}
+
+void ClientHandler::OnCursorChange(CefRefPtr<CefBrowser> browser,
+                                   CefCursorHandle cursor) {
+  if (!m_OSRHandler.get())
+    return;
+  m_OSRHandler->OnCursorChange(browser, cursor);
+}
+
+bool ClientHandler::StartDragging(CefRefPtr<CefBrowser> browser,
+    CefRefPtr<CefDragData> drag_data,
+    CefRenderHandler::DragOperationsMask allowed_ops,
+    int x, int y) {
+  if (!m_OSRHandler.get())
+    return false;
+  return m_OSRHandler->StartDragging(browser, drag_data, allowed_ops, x, y);
+}
+
+void ClientHandler::UpdateDragCursor(CefRefPtr<CefBrowser> browser,
+    CefRenderHandler::DragOperation operation) {
+  if (!m_OSRHandler.get())
+    return;
+  m_OSRHandler->UpdateDragCursor(browser, operation);
+}
+
 void ClientHandler::SetMainHwnd(ClientWindowHandle hwnd) {
   AutoLock lock_scope(this);
   m_MainHwnd = hwnd;