Add fast/inline to virtual/slimmingpaint and make the tests pass

Source/core/paint/BoxPainter.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/BoxPainter.h"
 
 #include "core/HTMLNames.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLFrameOwnerElement.h"
@@ skipping 36 matching lines @@
     LayoutRect paintRect = m_renderBox.borderBoxRect();
     paintRect.moveBy(paintOffset);
     paintBoxDecorationBackgroundWithRect(paintInfo, paintOffset, paintRect);
 }
 
 void BoxPainter::paintBoxDecorationBackgroundWithRect(PaintInfo& paintInfo, const LayoutPoint& paintOffset, const LayoutRect& paintRect)
 {
     RenderStyle* style = m_renderBox.style();
     BoxDecorationData boxDecorationData(*style, m_renderBox.canRenderBorderImage(), m_renderBox.backgroundHasOpaqueTopLayer(), paintInfo.context);
 
-    IntRect snappedPaintRect(pixelSnappedIntRect(paintRect));
-    // The document element is specified to paint its background infinitely.
-    DrawingRecorder recorder(paintInfo.context, &m_renderBox, paintInfo.phase,
-        m_renderBox.isDocumentElement() ? m_renderBox.view()->backgroundRect(&m_renderBox) : snappedPaintRect);
-
+    LayoutRect bounds;
+    if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
+        if (m_renderBox.isDocumentElement()) {
+            // The document element is specified to paint its background infinitely.
+            bounds = m_renderBox.view()->backgroundRect(&m_renderBox);
+        } else {
+            // Use the visual overflow rect here, because it will include overflow introduced by the theme.
+            bounds = m_renderBox.visualOverflowRect();
+            bounds.moveBy(paintOffset);
+        }
+    }
+    DrawingRecorder recorder(paintInfo.context, &m_renderBox, paintInfo.phase, bounds);
 
     // FIXME: Should eventually give the theme control over whether the box shadow should paint, since controls could have
     // custom shadows of their own.
     if (!m_renderBox.boxShadowShouldBeAppliedToBackground(boxDecorationData.bleedAvoidance()))
         paintBoxShadow(paintInfo, paintRect, style, Normal);
 
     GraphicsContextStateSaver stateSaver(*paintInfo.context, false);
     if (boxDecorationData.bleedAvoidance() == BackgroundBleedClipBackground) {
         stateSaver.save();
         RoundedRect border = style->getRoundedBorderFor(paintRect);
         paintInfo.context->clipRoundedRect(border);
     }
 
     // If we have a native theme appearance, paint that before painting our background.
     // The theme will tell us whether or not we should also paint the CSS background.
+    IntRect snappedPaintRect(pixelSnappedIntRect(paintRect));
     bool themePainted = boxDecorationData.hasAppearance && !RenderTheme::theme().paint(&m_renderBox, paintInfo, snappedPaintRect);
     if (!themePainted) {
         if (boxDecorationData.bleedAvoidance() == BackgroundBleedBackgroundOverBorder)
             paintBorder(m_renderBox, paintInfo, paintRect, style, boxDecorationData.bleedAvoidance());
 
         paintBackground(paintInfo, paintRect, boxDecorationData.backgroundColor, boxDecorationData.bleedAvoidance());
 
         if (boxDecorationData.hasAppearance)
             RenderTheme::theme().paintDecorations(&m_renderBox, paintInfo, snappedPaintRect);
     }
@@ skipping 2065 matching lines @@
 
     FloatPoint secondQuad[4];
     secondQuad[0] = quad[0];
     secondQuad[1] = FloatPoint(quad[0].x() - r1 * cx, quad[0].y() - r1 * cy);
     secondQuad[2] = quad[2];
     secondQuad[3] = quad[3];
     graphicsContext->clipPolygon(4, secondQuad, !secondEdgeMatches);
 }
 
 } // namespace blink