A DCHECK was validating a little to widely, moved it into the if that needed ...

chrome/renderer/render_widget.cc

 // Copyright (c) 2006-2008 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 "base/gfx/point.h"
 #include "base/gfx/size.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
@@ skipping 531 matching lines @@
   // 1) Ensures that we call WebView::Paint without a bunch of other junk
   //    on the call stack.
   // 2) Allows us to collect more damage rects before painting to help coalesce
   //    the work that we will need to do.
   MessageLoop::current()->PostTask(FROM_HERE, NewRunnableMethod(
       this, &RenderWidget::DoDeferredPaint));
 }
 
 void RenderWidget::DidScrollRect(WebWidget* webwidget, int dx, int dy,
                                  const gfx::Rect& clip_rect) {
-  // We only support scrolling along one axis at a time.
-  DCHECK((dx && !dy) || (!dx && dy));
+  if (dx != 0 && dy != 0) {
+    // We only support scrolling along one axis at a time.

[darin (slow to review), 2009/02/26 22:15:44]

this works by causing us to fall through to the slow path for scrolling, which
is fine.

+    DidScrollRect(webwidget, 0, dy, clip_rect);
+    dy = 0;
+  }
 
   bool intersects_with_painting = paint_rect_.Intersects(clip_rect);
 
   // If we already have a pending scroll operation or if this scroll operation
   // intersects the existing paint region, then just failover to invalidating.
   if (!scroll_rect_.IsEmpty() || intersects_with_painting) {
     if (!intersects_with_painting && scroll_rect_ == clip_rect) {
       // OK, we can just update the scroll delta (requires same scrolling axis)
       if (!dx && !scroll_delta_.x()) {
         scroll_delta_.set_y(scroll_delta_.y() + dy);
@@ skipping 240 matching lines @@
   for (; i < plugin_window_moves_.size(); ++i) {
     if (plugin_window_moves_[i].window == move.window) {
       plugin_window_moves_[i] = move;
       break;
     }
   }
 
   if (i == plugin_window_moves_.size())
     plugin_window_moves_.push_back(move);
 }