First version of PerformanceObserver

Source/core/timing/PerformanceEntry.cpp

Index: Source/core/timing/PerformanceEntry.cpp
diff --git a/Source/core/timing/PerformanceEntry.cpp b/Source/core/timing/PerformanceEntry.cpp
index 83b802b935c41dc76f5c7cc2ab48a31d5d61e4c9..0bac75547c123000c0a55c3ee017de620ba2b4e3 100644
--- a/Source/core/timing/PerformanceEntry.cpp
+++ b/Source/core/timing/PerformanceEntry.cpp
@@ -41,6 +41,7 @@ PerformanceEntry::PerformanceEntry(const String& name, const String& entryType,
     , m_entryType(entryType)
     , m_startTime(startTime)
     , m_duration(finishTime - startTime)
+    , m_entryTypeEnum(toEntryTypeEnum(entryType))
 {
 }
 
@@ -68,6 +69,21 @@ double PerformanceEntry::duration() const
     return m_duration;
 }
 
+PerformanceEntry::EntryType PerformanceEntry::toEntryTypeEnum(const String& entryType)
+{
+    if (equalIgnoringCase(entryType, "composite"))
+        return Composite;
+    if (equalIgnoringCase(entryType, "mark"))
+        return Mark;
+    if (equalIgnoringCase(entryType, "measure"))
+        return Measure;
+    if (equalIgnoringCase(entryType, "render"))
+        return Render;
+    if (equalIgnoringCase(entryType, "resource"))
+        return Resource;
+    return Invalid;
+}
+
 ScriptValue PerformanceEntry::toJSONForBinding(ScriptState* scriptState) const
 {
     V8ObjectBuilder result(scriptState);