Reenable box shadows when printing

Skia's PDF backend now supports blur masks!

(this is a revert of http://crrev.com/2689733002/)

BUG=chromium:127651,chromium:354073,chromium:691440

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: Id43393e48aa674c8a3a69c607c3512138d998dff
Reviewed-on: https://chromium-review.googlesource.com/538335
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Chris harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#480302}

third_party/WebKit/LayoutTests/TestExpectations

@@ -2511,6 +2511,9 @@ crbug.com/660384 external/wpt/webmessaging/with-ports/001.html [ Failure ]
 crbug.com/660384 external/wpt/webmessaging/without-ports/001.html [ Failure ]
 crbug.com/673526 external/wpt/webmessaging/message-channels/close.html [ Failure ]
 
+crbug.com/127651 paint/printing/print-box-shadow.html [ NeedsRebaseline ]
+crbug.com/127651 virtual/disable-spinvalidation/paint/printing/print-box-shadow.html [ NeedsRebaseline ]
+
 # Added 2016-12-12
 crbug.com/610835 http/tests/security/XFrameOptions/x-frame-options-deny-multiple-clients.html [ Failure Pass ]
 crbug.com/610835 virtual/mojo-loading/http/tests/security/XFrameOptions/x-frame-options-deny-multiple-clients.html [ Failure Pass ]

third_party/WebKit/Source/core/paint/BoxPainterBase.cpp

@@ -26,10 +26,6 @@ void BoxPainterBase::PaintNormalBoxShadow(const PaintInfo& info,
     return;
   GraphicsContext& context = info.context;
 
-  // https://bugs.chromium.org/p/skia/issues/detail?id=237
-  if (context.Printing())
-    return;
-
   FloatRoundedRect border = style.GetRoundedBorderFor(
       paint_rect, include_logical_left_edge, include_logical_right_edge);
 
@@ -153,10 +149,6 @@ void BoxPainterBase::PaintInsetBoxShadowInBounds(
   DCHECK(style.BoxShadow());
   GraphicsContext& context = info.context;
 
-  // https://bugs.chromium.org/p/skia/issues/detail?id=237
-  if (context.Printing())
-    return;
-
   bool is_horizontal = style.IsHorizontalWritingMode();
   GraphicsContextStateSaver state_saver(context, false);