Fix ThumbnailGenerator on Windows.

chrome/renderer/render_widget.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/render_widget.h"
 
 #include "app/surface/transport_dib.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
@@ skipping 801 matching lines @@
   if (webwidget_)
     webwidget_->confirmComposition();
 }
 
 // This message causes the renderer to render an image of the
 // desired_size, regardless of whether the tab is hidden or not.
 void RenderWidget::OnMsgPaintAtSize(const TransportDIB::Handle& dib_handle,
                                     int tag,
                                     const gfx::Size& page_size,
                                     const gfx::Size& desired_size) {
-  if (!webwidget_ || dib_handle == TransportDIB::DefaultHandleValue())
+  if (!webwidget_ || !TransportDIB::is_valid(dib_handle)) {
+    if (TransportDIB::is_valid(dib_handle)) {
+      // Close our unused handle.
+#if defined(OS_WIN)
+      ::CloseHandle(dib_handle);
+#elif defined(OS_MACOSX)
+      base::SharedMemory::CloseHandle(dib_handle);
+#endif
+    }
     return;
+  }
 
   if (page_size.IsEmpty() || desired_size.IsEmpty()) {
     // If one of these is empty, then we just return the dib we were
     // given, to avoid leaking it.
     Send(new ViewHostMsg_PaintAtSize_ACK(routing_id_, tag, desired_size));
     return;
   }
 
   // Map the given DIB ID into this process, and unmap it at the end
   // of this function.
-  scoped_ptr<TransportDIB> paint_at_size_buffer(TransportDIB::Map(dib_handle));
-
-  DCHECK(paint_at_size_buffer.get());
-  if (!paint_at_size_buffer.get())
-    return;
+  scoped_ptr<TransportDIB> paint_at_size_buffer(
+      TransportDIB::CreateWithHandle(dib_handle));
 
   gfx::Size canvas_size = page_size;
   float x_scale = static_cast<float>(desired_size.width()) /
                   static_cast<float>(canvas_size.width());
   float y_scale = static_cast<float>(desired_size.height()) /
                   static_cast<float>(canvas_size.height());
 
   gfx::Rect orig_bounds(canvas_size);
   canvas_size.set_width(static_cast<int>(canvas_size.width() * x_scale));
   canvas_size.set_height(static_cast<int>(canvas_size.height() * y_scale));
@@ skipping 164 matching lines @@
 
 void RenderWidget::CleanupWindowInPluginMoves(gfx::PluginWindowHandle window) {
   for (WebPluginGeometryVector::iterator i = plugin_window_moves_.begin();
        i != plugin_window_moves_.end(); ++i) {
     if (i->window == window) {
       plugin_window_moves_.erase(i);
       break;
     }
   }
 }