Updated error message in PerformanceObserver.observe

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/timing/PerformanceObserver.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/PerformanceObserverCallback.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/timing/PerformanceBase.h"
@@ skipping 31 matching lines @@
   }
 
   PerformanceEntryTypeMask entryTypes = PerformanceEntry::Invalid;
   if (observerInit.hasEntryTypes() && observerInit.entryTypes().size()) {
     const Vector<String>& sequence = observerInit.entryTypes();
     for (const auto& entryTypeString : sequence)
       entryTypes |= PerformanceEntry::toEntryTypeEnum(entryTypeString);
   }
   if (entryTypes == PerformanceEntry::Invalid) {
     exceptionState.throwTypeError(
-        "A Performance Observer MUST have a non-empty entryTypes attribute.");
+        "A Performance Observer MUST have a valid entryTypes attribute.");

[Yoav Weiss, 2016/11/04 21:49:16]

Just to clarify, if one of the entries is valid, this doesn't throw, right?
If so, maybe the error thrown should reflect that? "A Performance Observer MUST
have at least one valid entryType in its entryTypes attribute."?

[sunjian, 2016/11/09 23:27:58]

Done.

     return;
   }
   m_filterOptions = entryTypes;
   if (m_isRegistered)
     m_performance->updatePerformanceObserverFilterOptions();
   else
     m_performance->registerPerformanceObserver(*this);
   m_isRegistered = true;
 }
 
@@ skipping 34 matching lines @@
   visitor->trace(m_callback);
   visitor->trace(m_performance);
   visitor->trace(m_performanceEntries);
 }
 
 DEFINE_TRACE_WRAPPERS(PerformanceObserver) {
   visitor->traceWrappers(m_callback);
 }
 
 }  // namespace blink