Native side implementation for Performance.measure()

Summary:
Changelog: [Internal]

This implements the C++ side logic of handling `Performance.measure` calls.

Since measures may refer to earlier logged marks by name, we need to keep track of the former. I also use a fixed size (circular) buffer to prevent the marks from piling forever.

Also adds implementation of clearing marks/measures, as per standard.

Reviewed By: mdvacca

Differential Revision: D41756928

fbshipit-source-id: 19dce28d6af4c5646274e6d5db20b41869282780

Libraries/WebPerformance/NativePerformanceObserver.cpp

@@ -15,6 +15,8 @@ static PerformanceEntryType stringToPerformanceEntryType(
     const std::string &entryType) {
   if (entryType == "mark") {
     return PerformanceEntryType::MARK;
+  } else if (entryType == "measure") {
+    return PerformanceEntryType::MEASURE;
   } else {
     return PerformanceEntryType::UNDEFINED;
   }