Revert "Log to UMA why we would load a third-party frame"

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 40ec07d36da6841e83fe3673db9bcf585c886645..0844a8866f7e44e8c80e1de6abf56ca11efc538d 100644
--- a/third_party/WebKit/Source/core/dom/Document.h
+++ b/third_party/WebKit/Source/core/dom/Document.h
@@ -236,29 +236,6 @@ enum CreateElementFlags {
   CreatedByFragmentParser = CreatedByParser | AsynchronousCustomElements,
 };
 
-// Collect data about deferred loading of offscreen cross-origin documents. All
-// cross-origin documents log Created. Only those that would load log a reason.
-// We can then see the % of cross-origin documents that never have to load.
-// See https://crbug.com/635105.
-// Logged to UMA, don't re-arrange entries without creating a new histogram.
-enum WouldLoadReason {
-  Created,
-  // If outer and inner frames aren't in the same process we can't determine
-  // if the inner frame is visible, so just load it.
-  // TODO(dgrogan): Revisit after https://crbug.com/650433 is fixed.
-  WouldLoadOutOfProcess,
-  // The next four indicate frames that are probably used for cross-origin
-  // communication.
-  WouldLoadDisplayNone,
-  WouldLoadZeroByZero,
-  WouldLoadAbove,
-  WouldLoadLeft,
-  // We have to load documents in visible frames.
-  WouldLoadVisible,
-
-  WouldLoadReasonEnd
-};
-
 using DocumentClassFlags = unsigned char;
 
 class CORE_EXPORT Document : public ContainerNode,
@@ -1309,8 +1286,7 @@ class CORE_EXPORT Document : public ContainerNode,
 
   bool isInMainFrame() const;
 
-  void maybeRecordLoadReason(WouldLoadReason);
-  WouldLoadReason wouldLoadReason() { return m_wouldLoadReason; }
+  void onVisibilityMaybeChanged(bool visible);
 
   PropertyRegistry* propertyRegistry();
 
@@ -1665,7 +1641,7 @@ class CORE_EXPORT Document : public ContainerNode,
 
   Member<SnapCoordinator> m_snapCoordinator;
 
-  WouldLoadReason m_wouldLoadReason;
+  bool m_visibilityWasLogged;
 
   Member<PropertyRegistry> m_propertyRegistry;
 };