This adds in the ability for Chrome to generate windows with snapshots of all...

chrome/browser/renderer_host/render_widget_host.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/browser/renderer_host/render_widget_host.h"
 
 #include "base/auto_reset.h"
 #include "base/histogram.h"
 #include "base/keyboard_codes.h"
 #include "base/message_loop.h"
@@ skipping 109 matching lines @@
   Destroy();
 }
 
 void RenderWidgetHost::OnMessageReceived(const IPC::Message &msg) {
   bool msg_is_ok = true;
   IPC_BEGIN_MESSAGE_MAP_EX(RenderWidgetHost, msg, msg_is_ok)
     IPC_MESSAGE_HANDLER(ViewHostMsg_RenderViewReady, OnMsgRenderViewReady)
     IPC_MESSAGE_HANDLER(ViewHostMsg_RenderViewGone, OnMsgRenderViewGone)
     IPC_MESSAGE_HANDLER(ViewHostMsg_Close, OnMsgClose)
     IPC_MESSAGE_HANDLER(ViewHostMsg_RequestMove, OnMsgRequestMove)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_PaintAtSize_ACK, OnMsgPaintAtSizeAck)
     IPC_MESSAGE_HANDLER(ViewHostMsg_UpdateRect, OnMsgUpdateRect)
     IPC_MESSAGE_HANDLER(ViewHostMsg_CreateVideo, OnMsgCreateVideo)
     IPC_MESSAGE_HANDLER(ViewHostMsg_UpdateVideo, OnMsgUpdateVideo)
     IPC_MESSAGE_HANDLER(ViewHostMsg_DestroyVideo, OnMsgDestroyVideo)
     IPC_MESSAGE_HANDLER(ViewHostMsg_HandleInputEvent_ACK, OnMsgInputEventAck)
     IPC_MESSAGE_HANDLER(ViewHostMsg_Focus, OnMsgFocus)
     IPC_MESSAGE_HANDLER(ViewHostMsg_Blur, OnMsgBlur)
     IPC_MESSAGE_HANDLER(ViewHostMsg_FocusedNodeChanged, OnMsgFocusedNodeChanged)
     IPC_MESSAGE_HANDLER(ViewHostMsg_SetCursor, OnMsgSetCursor)
     IPC_MESSAGE_HANDLER(ViewHostMsg_ImeUpdateStatus, OnMsgImeUpdateStatus)
@@ skipping 133 matching lines @@
   view_ = NULL;
 }
 
 void RenderWidgetHost::SetIsLoading(bool is_loading) {
   is_loading_ = is_loading;
   if (!view_)
     return;
   view_->SetIsLoading(is_loading);
 }
 
+void RenderWidgetHost::PaintAtSize(TransportDIB::Handle dib_handle,
+                                   const gfx::Size& size) {
+  // Ask the renderer to create a bitmap regardless of whether it's
+  // hidden, being resized, redrawn, etc., and to scale it by the
+  // scale factor given.
+  Send(new ViewMsg_PaintAtSize(routing_id_, dib_handle, size));
+}
+
 BackingStore* RenderWidgetHost::GetBackingStore(bool force_create) {
   // We should not be asked to paint while we are hidden.  If we are hidden,
   // then it means that our consumer failed to call WasRestored. If we're not
   // force creating the backing store, it's OK since we can feel free to give
   // out our cached one if we have it.
   DCHECK(!is_hidden_ || !force_create) <<
       "GetBackingStore called while hidden!";
 
   // We should never be called recursively; this can theoretically lead to
   // infinite recursion and almost certainly leads to lower performance.
@@ skipping 376 matching lines @@
 }
 
 void RenderWidgetHost::OnMsgRequestMove(const gfx::Rect& pos) {
   // Note that we ignore the position.
   if (view_) {
     view_->SetSize(pos.size());
     Send(new ViewMsg_Move_ACK(routing_id_));
   }
 }
 
+void RenderWidgetHost::OnMsgPaintAtSizeAck(
+    const TransportDIB::Handle& dib_handle, const gfx::Size& size) {
+  if (painting_observer_) {
+    painting_observer_->WidgetDidReceivePaintAtSizeAck(this, dib_handle, size);
+  }
+}
+
 void RenderWidgetHost::OnMsgUpdateRect(
     const ViewHostMsg_UpdateRect_Params& params) {
   TimeTicks paint_start = TimeTicks::Now();
 
   // Update our knowledge of the RenderWidget's size.
   current_size_ = params.view_size;
 
   bool is_resize_ack =
       ViewHostMsg_UpdateRect_Flags::is_resize_ack(params.flags);
 
@@ skipping 385 matching lines @@
     // of this key event.
     if (!processed && !is_hidden_ && !front_item.skip_in_browser) {
       UnhandledKeyboardEvent(front_item);
 
       // WARNING: This RenderWidgetHost can be deallocated at this point
       // (i.e.  in the case of Ctrl+W, where the call to
       // UnhandledKeyboardEvent destroys this RenderWidgetHost).
     }
   }
 }