Deferred frame loading stats v2

third_party/WebKit/Source/core/dom/Document.h

Index: third_party/WebKit/Source/core/dom/Document.h
diff --git a/third_party/WebKit/Source/core/dom/Document.h b/third_party/WebKit/Source/core/dom/Document.h
index dbf24300948695646d45183b83c1007d842adeab..f11cbbb45d1cf6d695416cc521d4f82ebe31dc39 100644
--- a/third_party/WebKit/Source/core/dom/Document.h
+++ b/third_party/WebKit/Source/core/dom/Document.h
@@ -235,6 +235,19 @@ enum CreateElementFlags {
   CreatedByFragmentParser = CreatedByParser | AsynchronousCustomElements,
 };
 
+// Logged to UMA, so don't re-arrange them without creating a new histogram.

[dcheng, 2016/10/08 00:46:22]

Nit: add a comment that describes the purpose of an enum. Perhaps some comments
on the enum values would also be useful (for example, the purpose of
WouldLoadOutOfProcess is not as clear to me)

[dgrogan, 2016/10/13 01:06:21]

Done.

+enum WouldLoadReason {
+  Created,
+  WouldLoadDisplayNone,
+  WouldLoadOutOfProcess,
+  WouldLoadZeroByZero,
+  WouldLoadAbove,
+  WouldLoadLeft,
+  WouldLoadVisible,
+
+  WouldLoadReasonEnd
+};
+
 using DocumentClassFlags = unsigned char;
 
 class CORE_EXPORT Document : public ContainerNode,
@@ -1280,7 +1293,8 @@ class CORE_EXPORT Document : public ContainerNode,
 
   bool isInMainFrame() const;
 
-  void onVisibilityMaybeChanged(bool visible);
+  void wouldLoadBecause(WouldLoadReason);
+  WouldLoadReason wouldLoadReason() { return m_wouldLoadReason; }
 
   PropertyRegistry* propertyRegistry();
 
@@ -1636,7 +1650,7 @@ class CORE_EXPORT Document : public ContainerNode,
 
   Member<SnapCoordinator> m_snapCoordinator;
 
-  bool m_visibilityWasLogged;
+  WouldLoadReason m_wouldLoadReason;
 
   Member<PropertyRegistry> m_propertyRegistry;
 };