Sync IntersectionObserver IDL with the spec

third_party/WebKit/Source/core/dom/IntersectionObserver.cpp

 // Copyright 2016 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/dom/IntersectionObserver.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/css/parser/CSSParserTokenRange.h"
 #include "core/css/parser/CSSTokenizer.h"
 #include "core/dom/Element.h"
@@ skipping 89 matching lines @@
                 "rootMargin must be specified in pixels or percent.");
         }
         break;
       default:
         exceptionState.throwDOMException(
             SyntaxError, "rootMargin must be specified in pixels or percent.");
     }
   }
 }
 
-void parseThresholds(const DoubleOrDoubleArray& thresholdParameter,
+void parseThresholds(const DoubleOrDoubleSequence& thresholdParameter,
                      Vector<float>& thresholds,
                      ExceptionState& exceptionState) {
   if (thresholdParameter.isDouble()) {
     thresholds.append(static_cast<float>(thresholdParameter.getAsDouble()));
   } else {
-    for (auto thresholdValue : thresholdParameter.getAsDoubleArray())
+    for (auto thresholdValue : thresholdParameter.getAsDoubleSequence())
       thresholds.append(static_cast<float>(thresholdValue));
   }
 
   for (auto thresholdValue : thresholds) {
     if (std::isnan(thresholdValue) || thresholdValue < 0.0 ||
         thresholdValue > 1.0) {
       exceptionState.throwRangeError(
           "Threshold values must be numbers between 0 and 1");
       break;
     }
@@ skipping 25 matching lines @@
     root = getRootNode(toDocument(context));
   }
   if (!root) {
     exceptionState.throwDOMException(
         HierarchyRequestError,
         "Unable to get root node in main frame to track.");
     return nullptr;
   }
 
   Vector<Length> rootMargin;
-  if (observerInit.hasRootMargin())
-    parseRootMargin(observerInit.rootMargin(), rootMargin, exceptionState);
+  parseRootMargin(observerInit.rootMargin(), rootMargin, exceptionState);
   if (exceptionState.hadException())
     return nullptr;
 
   Vector<float> thresholds;
-  if (observerInit.hasThreshold())
-    parseThresholds(observerInit.threshold(), thresholds, exceptionState);
-  else
-    thresholds.append(0);
+  parseThresholds(observerInit.threshold(), thresholds, exceptionState);
   if (exceptionState.hadException())
     return nullptr;
 
   return new IntersectionObserver(callback, *root, rootMargin, thresholds);
 }
 
 IntersectionObserver* IntersectionObserver::create(
     const Vector<Length>& rootMargin,
     const Vector<float>& thresholds,
     Document* document,
@@ skipping 257 matching lines @@
 
 DEFINE_TRACE(IntersectionObserver) {
   visitor->template registerWeakMembers<
       IntersectionObserver, &IntersectionObserver::clearWeakMembers>(this);
   visitor->trace(m_callback);
   visitor->trace(m_observations);
   visitor->trace(m_entries);
 }
 
 }  // namespace blink