Render using WebPaintSurface.

webkit/tools/test_shell/webwidget_host_win.cc

Index: webkit/tools/test_shell/webwidget_host_win.cc
===================================================================
--- webkit/tools/test_shell/webwidget_host_win.cc	(revision 73503)
+++ webkit/tools/test_shell/webwidget_host_win.cc	(working copy)
@@ -21,6 +21,7 @@
 using WebKit::WebKeyboardEvent;
 using WebKit::WebMouseEvent;
 using WebKit::WebMouseWheelEvent;
+using WebKit::WebPaintSurface;
 using WebKit::WebPopupMenu;
 using WebKit::WebScreenInfo;
 using WebKit::WebScreenInfoFactory;
@@ -137,6 +138,22 @@
   return DefWindowProc(hwnd, message, wparam, lparam);;
 }
 
+#if WEBKIT_USING_PAINTSURFACE
+
+WebPaintSurface* WebWidgetHost::GetPaintSurface() {
+  gfx::Size widget_size = webwidget_->size();
+  if (!paint_surface_.get() || paint_surface_->size() != widget_size) {
+    // This may result in discarding a previously allocated paint surface,
+    // which had not yet been fully rendered (see DidModifyPaintSurface).
+    pending_paint_surface_.reset(
+        new SimpleWebPaintSurfaceImpl(this, widget_size));
+    return pending_paint_surface_.get();
+  }
+  return paint_surface_.get();
+}
+
+#else  // WEBKIT_USING_PAINTSURFACE
+
 void WebWidgetHost::DidInvalidateRect(const gfx::Rect& damaged_rect) {
   DLOG_IF(WARNING, painting_) << "unexpected invalidation while painting";
 
@@ -176,6 +193,8 @@
   InvalidateRect(view_, &r, FALSE);
 }
 
+#endif  // WEBKIT_USING_PAINTSURFACE
+
 void WebWidgetHost::ScheduleComposite() {
   if (!webwidget_)
     return;
@@ -231,6 +250,49 @@
 }
 
 void WebWidgetHost::Paint() {
+#if WEBKIT_USING_PAINTSURFACE
+  // Paint to the screen
+  PAINTSTRUCT ps;
+  BeginPaint(view_, &ps);
+
+  gfx::Rect damage_rect(ps.rcPaint);
+  gfx::Rect canvas_rect;
+
+  if (paint_surface_.get()) {
+    canvas_rect.set_size(paint_surface_->size());
+    canvas_rect = canvas_rect.Intersect(damage_rect);
+    if (!canvas_rect.IsEmpty()) {
+      skia::PlatformCanvas* canvas = paint_surface_->canvas();
+      canvas->getTopPlatformDevice().drawToHDC(ps.hdc,
+                                               canvas_rect.x(),
+                                               canvas_rect.y(),
+                                               &canvas_rect.ToRECT());
+    }
+  }
+
+  if (damage_rect.right() > canvas_rect.right()) {
+    // Paint right edge.
+    gfx::Rect r(canvas_rect.right(),
+                damage_rect.y(),
+                damage_rect.right() - canvas_rect.right(),
+                damage_rect.height());
+    FillRect(ps.hdc, &r.ToRECT(), (HBRUSH)GetStockObject(WHITE_BRUSH));
+  }
+
+  if (damage_rect.bottom() > canvas_rect.bottom()) {
+    // Paint bottom edge, possibly overpainting the corner for simplicity.
+    gfx::Rect r(damage_rect.x(),
+                canvas_rect.bottom(),
+                damage_rect.width(),
+                damage_rect.bottom() - canvas_rect.bottom());
+    FillRect(ps.hdc, &r.ToRECT(), (HBRUSH)GetStockObject(WHITE_BRUSH));
+  }
+
+  EndPaint(view_, &ps);
+
+  if (paint_surface_.get())
+    paint_surface_->DidCopyPaintSurface();
+#else
   RECT r;
   GetClientRect(view_, &r);
   gfx::Rect client_rect(r);
@@ -286,6 +348,7 @@
 
   // Draw children
   UpdateWindow(view_);
+#endif
 }
 
 WebScreenInfo WebWidgetHost::GetScreenInfo() {
@@ -371,6 +434,15 @@
   scroll_dy_ = 0;
 }
 
+void WebWidgetHost::DidModifyPaintSurface(const gfx::Rect& bounds) {
+  // If there is a pending paint surface, then we can now consider it
+  // up-to-date and usable.
+  if (pending_paint_surface_.get())
+    paint_surface_.reset(pending_paint_surface_.release());
+
+  InvalidateRect(view_, &bounds.ToRECT(), FALSE);
+}
+
 void WebWidgetHost::PaintRect(const gfx::Rect& rect) {
 #ifndef NDEBUG
   DCHECK(!painting_);