Add a new document lifecycle; CompositingInputsClean

third_party/WebKit/Source/core/dom/DocumentLifecycle.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 188 matching lines @@
         return true;
       if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled() &&
           next_state == kInCompositingUpdate)
         return true;
       if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() &&
           next_state == kInPrePaint)
         return true;
       break;
     case kInCompositingUpdate:
       DCHECK(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
-      return next_state == kCompositingClean;
+      // Once we are in the compositing update, we can either just clean the
+      // inputs or do the whole of compositing.
+      return next_state == kCompositingInputsClean ||
+             next_state == kCompositingClean;
+    case kCompositingInputsClean:
+      DCHECK(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
+      // We can return to style re-calc, layout, or the start of compositing.
+      if (next_state == kInStyleRecalc)
+        return true;
+      if (next_state == kInPreLayout)
+        return true;
+      if (next_state == kInCompositingUpdate)
+        return true;
+      // Otherwise, we can continue onwards.
+      if (next_state == kCompositingClean)
+        return true;
     case kCompositingClean:
       DCHECK(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
       if (next_state == kInStyleRecalc)
         return true;
       if (next_state == kInPreLayout)
         return true;
       if (next_state == kInCompositingUpdate)
         return true;
       if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled()) {
         if (next_state == kInPrePaint)
@@ skipping 60 matching lines @@
 
 bool DocumentLifecycle::CanRewindTo(LifecycleState next_state) const {
   if (StateTransitionDisallowed())
     return false;
 
   // This transition is bogus, but we've whitelisted it anyway.
   if (g_deprecated_transition_stack &&
       state_ == g_deprecated_transition_stack->From() &&
       next_state == g_deprecated_transition_stack->To())
     return true;
+  // TODO(smcgruer): Not sure if this is correct.
   return state_ == kStyleClean || state_ == kLayoutSubtreeChangeClean ||
          state_ == kAfterPerformLayout || state_ == kLayoutClean ||
-         state_ == kCompositingClean || state_ == kPaintInvalidationClean ||
-         state_ == kPrePaintClean || state_ == kPaintClean;
+         state_ == kCompositingInputsClean || state_ == kCompositingClean ||
+         state_ == kPaintInvalidationClean || state_ == kPrePaintClean ||
+         state_ == kPaintClean;
 }
 
 #define DEBUG_STRING_CASE(StateName) \
   case DocumentLifecycle::StateName: \
     return #StateName
 
 static WTF::String StateAsDebugString(
     const DocumentLifecycle::LifecycleState& state) {
   switch (state) {
     DEBUG_STRING_CASE(kUninitialized);
     DEBUG_STRING_CASE(kInactive);
     DEBUG_STRING_CASE(kVisualUpdatePending);
     DEBUG_STRING_CASE(kInStyleRecalc);
     DEBUG_STRING_CASE(kStyleClean);
     DEBUG_STRING_CASE(kInLayoutSubtreeChange);
     DEBUG_STRING_CASE(kLayoutSubtreeChangeClean);
     DEBUG_STRING_CASE(kInPreLayout);
     DEBUG_STRING_CASE(kInPerformLayout);
     DEBUG_STRING_CASE(kAfterPerformLayout);
     DEBUG_STRING_CASE(kLayoutClean);
     DEBUG_STRING_CASE(kInCompositingUpdate);
+    DEBUG_STRING_CASE(kCompositingInputsClean);
     DEBUG_STRING_CASE(kCompositingClean);
     DEBUG_STRING_CASE(kInPaintInvalidation);
     DEBUG_STRING_CASE(kPaintInvalidationClean);
     DEBUG_STRING_CASE(kInPrePaint);
     DEBUG_STRING_CASE(kPrePaintClean);
     DEBUG_STRING_CASE(kInPaint);
     DEBUG_STRING_CASE(kPaintClean);
     DEBUG_STRING_CASE(kStopping);
     DEBUG_STRING_CASE(kStopped);
   }
@@ skipping 27 matching lines @@
       << " to " << StateAsDebugString(state) << ".";
 #endif
   state_ = state;
 }
 
 bool DocumentLifecycle::ThrottlingAllowed() const {
   return g_allow_throttling_count;
 }
 
 }  // namespace blink