Slimming Paint phase 2 compositing algorithm plumbing

Source/core/dom/DocumentLifecycle.cpp

Index: Source/core/dom/DocumentLifecycle.cpp
diff --git a/Source/core/dom/DocumentLifecycle.cpp b/Source/core/dom/DocumentLifecycle.cpp
index 25abf3c9c49481710b9a62c380547cdd91aec1c1..7b2ed8c0fe793b6ae7c41669204a6b853437c491 100644
--- a/Source/core/dom/DocumentLifecycle.cpp
+++ b/Source/core/dom/DocumentLifecycle.cpp
@@ -31,6 +31,7 @@
 #include "config.h"
 #include "core/dom/DocumentLifecycle.h"
 
+#include "platform/RuntimeEnabledFeatures.h"
 #include "wtf/Assertions.h"
 
 namespace blink {
@@ -172,6 +173,8 @@ bool DocumentLifecycle::canAdvanceTo(State state) const
             return true;
         if (state == InCompositingUpdate)
             return true;
+        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && state == InPaintInvalidation)

[chrishtr, 2015/08/13 17:28:31]

Also add the paint lifecycle stage in this CL.

[pdr., 2015/08/13 20:54:59]

Done.

As discussed offline, it'll be difficult to do the spv2 transition reusing the
existing compositing lifecycle phase. We now have four new states for
InPaintForSlimmingPaintV2 and InCompositingForSlimmingPaintV2 (and *Clean
versions, respectively). Two phases are not strictly needed but I think they'll
become useful very soon.

+            return true;
         break;
     case InCompositingUpdate:
         return state == CompositingClean;