Add more detail to same-origin attribution indicating self|ancestor|descendant

third_party/WebKit/Source/core/timing/Performance.cpp

Index: third_party/WebKit/Source/core/timing/Performance.cpp
diff --git a/third_party/WebKit/Source/core/timing/Performance.cpp b/third_party/WebKit/Source/core/timing/Performance.cpp
index dc017d37dfcfcce2775ac3eb87e89fd0bbbacab9..7137b1a18193c88bebab5984ea8c3bb4c291ef9a 100644
--- a/third_party/WebKit/Source/core/timing/Performance.cpp
+++ b/third_party/WebKit/Source/core/timing/Performance.cpp
@@ -48,8 +48,12 @@ static const double kLongTaskThreshold = 0.05;
 static const char kUnknownAttribution[] = "unknown";
 static const char kAmbiguousAttribution[] = "multiple-contexts";
 static const char kSameOriginAttribution[] = "same-origin";
-static const char kAncestorAttribution[] = "cross-origin-ancestor";
-static const char kDescendantAttribution[] = "cross-origin-descendant";
+static const char kSameOriginSelfAttribution[] = "same-origin-self";
+static const char kSameOriginAncestorAttribution[] = "same-origin-ancestor";
+static const char kSameOriginDescendantAttribution[] = "same-origin-descendant";
+static const char kCrossOriginAncestorAttribution[] = "cross-origin-ancestor";
+static const char kCrossOriginDescendantAttribution[] =
+    "cross-origin-descendant";
 static const char kCrossOriginAttribution[] = "cross-origin-unreachable";
 
 namespace blink {
@@ -68,6 +72,16 @@ String getFrameAttribute(HTMLFrameOwnerElement* frameOwner,
   return attrValue;
 }
 
+const char* sameOriginAttribution(Frame* observerFrame, Frame* culpritFrame) {
+  if (observerFrame == culpritFrame)
+    return kSameOriginSelfAttribution;
+  if (observerFrame->tree().isDescendantOf(culpritFrame))
+    return kSameOriginAncestorAttribution;
+  if (culpritFrame->tree().isDescendantOf(observerFrame))
+    return kSameOriginDescendantAttribution;
+  return kSameOriginAttribution;
+}
+
 }  // namespace
 
 static double toTimeOrigin(LocalFrame* frame) {
@@ -185,7 +199,8 @@ std::pair<String, DOMWindow*> Performance::sanitizedAttribution(
   DCHECK(culpritFrame);
   if (canAccessOrigin(observerFrame, culpritFrame)) {
     // From accessible frames or same origin, return culprit location URL.
-    return std::make_pair(kSameOriginAttribution, culpritFrame->domWindow());
+    return std::make_pair(sameOriginAttribution(observerFrame, culpritFrame),
+                          culpritFrame->domWindow());
   }
   // For cross-origin, if the culprit is the descendant or ancestor of
   // observer then indicate the *closest* cross-origin frame between
@@ -202,11 +217,11 @@ std::pair<String, DOMWindow*> Performance::sanitizedAttribution(
         lastCrossOriginFrame = frame;
       }
     }
-    return std::make_pair(kDescendantAttribution,
+    return std::make_pair(kCrossOriginDescendantAttribution,
                           lastCrossOriginFrame->domWindow());
   }
   if (observerFrame->tree().isDescendantOf(culpritFrame)) {
-    return std::make_pair(kAncestorAttribution, nullptr);
+    return std::make_pair(kCrossOriginAncestorAttribution, nullptr);
   }
   return std::make_pair(kCrossOriginAttribution, nullptr);
 }