Enable slimming paint for all layout tests

LayoutTests/TestExpectations

Index: LayoutTests/TestExpectations
diff --git a/LayoutTests/TestExpectations b/LayoutTests/TestExpectations
index 91df208c1f467bdc7a116d425d7ed13b9e424ed5..0afcc28a62084c0c66b4e69934c79228fc789374 100644
--- a/LayoutTests/TestExpectations
+++ b/LayoutTests/TestExpectations
@@ -29,6 +29,13 @@ crbug.com/474440 [ Mac ] plugins/destroy-reentry.html [ Pass Timeout ]
 
 crbug.com/441840 [ Mac XP ] cssom/ahem-ex-units.html [ Failure ]
 
+crbug.com/497950 http/tests/loading/simple-subframe.html [ NeedsManualRebaseline ]
+crbug.com/497950 http/tests/local/file-url-sent-as-referer.html [ NeedsRebaseline ]
+crbug.com/497950 http/tests/mime/png-image-with-x-png-mime-type.html [ NeedsRebaseline ]
+crbug.com/497950 http/tests/misc/acid2-pixel.html [ NeedsRebaseline ]
+crbug.com/497950 http/tests/misc/iframe404.html [ NeedsRebaseline ]
+crbug.com/497950 http/tests/misc/location-replace-crossdomain.html [ NeedsRebaseline ]
+
 # In root-layer-scrolls, the scrollbars make the scroll offsets difficult to compute.
 crbug.com/487948 virtual/rootlayerscrolls/fast/scrolling/keyboard-scroll-page-scale.html [ Failure ]
 crbug.com/487948 virtual/rootlayerscrolls/fast/scrolling/editor-command-scroll-page-scale.html [ Failure ]
@@ -1279,7 +1286,8 @@ crbug.com/396791 [ Debug ] virtual/threaded/printing/print-close-crash.html [ Pa
 
 crbug.com/431172 [ XP ] http/tests/serviceworker/fetch-event.html [ Pass Timeout ]
 
-crbug.com/448461 http/tests/loading/simple-subframe.html [ Failure Pass ]
+# TODO(wangxianzhu): Restore this after rebaseline
+# crbug.com/448461 http/tests/loading/simple-subframe.html [ Failure Pass ]
 
 crbug.com/407993 [ Win ] media/encrypted-media/prefixed/encrypted-media-events.html [ Crash Pass ]