Fix slimming paint clipping and add a debug fill color

Source/core/paint/LineBoxListPainter.cpp

 // Copyright 2014 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 "config.h"
 #include "core/paint/LineBoxListPainter.h"
 
 #include "core/paint/InlinePainter.h"
 #include "core/paint/ViewDisplayList.h"
 #include "core/rendering/InlineFlowBox.h"
@@ skipping 15 matching lines @@
     ASSERT(renderer->isRenderBlock() || (renderer->isRenderInline() && renderer->hasLayer())); // The only way an inline could paint like this is if it has a layer.
 
     // If we have no lines then we have no work to do.
     if (!m_renderLineBoxList.firstLineBox())
         return;
 
     if (!m_renderLineBoxList.anyLineIntersectsRect(renderer, paintInfo.rect, paintOffset))
         return;
 
     PaintInfo info(paintInfo);
-    PaintCommandRecorder recorder(paintInfo.context, renderer, paintInfo.phase, renderer->borderBoundingBox());
+    PaintCommandRecorder recorder(paintInfo.context, renderer, paintInfo.phase, pixelSnappedIntRect(paintOffset, renderer->borderBoundingBox().size()));
     ListHashSet<RenderInline*> outlineObjects;
     info.setOutlineObjects(&outlineObjects);
 
     // See if our root lines intersect with the dirty rect. If so, then we paint
     // them. Note that boxes can easily overlap, so we can't make any assumptions
     // based off positions of our first line box or our last line box.
     for (InlineFlowBox* curr = m_renderLineBoxList.firstLineBox(); curr; curr = curr->nextLineBox()) {
         if (m_renderLineBoxList.lineIntersectsDirtyRect(renderer, curr, info, paintOffset)) {
             RootInlineBox& root = curr->root();
             curr->paint(info, paintOffset, root.lineTop(), root.lineBottom());
         }
     }
 
     if (info.phase == PaintPhaseOutline || info.phase == PaintPhaseSelfOutline || info.phase == PaintPhaseChildOutlines) {
         ListHashSet<RenderInline*>::iterator end = info.outlineObjects()->end();
         for (ListHashSet<RenderInline*>::iterator it = info.outlineObjects()->begin(); it != end; ++it) {
             RenderInline* flow = *it;
             InlinePainter(*flow).paintOutline(info, paintOffset);
         }
         info.outlineObjects()->clear();
     }
 }
 
 } // namespace blink