Construct URLSearchParams from sequence initializer.

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

Index: third_party/WebKit/Source/core/dom/URLSearchParams.cpp
diff --git a/third_party/WebKit/Source/core/dom/URLSearchParams.cpp b/third_party/WebKit/Source/core/dom/URLSearchParams.cpp
index 30ba1da486351f1baf909e7e40e874f864b3404d..fac8afdfeed40681ab37a4d71f38eb1145d06b3d 100644
--- a/third_party/WebKit/Source/core/dom/URLSearchParams.cpp
+++ b/third_party/WebKit/Source/core/dom/URLSearchParams.cpp
@@ -39,20 +39,44 @@ class URLSearchParamsIterationSource final
 
 }  // namespace
 
-URLSearchParams* URLSearchParams::create(const URLSearchParamsInit& init) {
+URLSearchParams* URLSearchParams::create(const URLSearchParamsInit& init,
+                                         ExceptionState& exceptionState) {
   if (init.isUSVString()) {
     const String& queryString = init.getAsUSVString();
     if (queryString.startsWith('?'))
       return new URLSearchParams(queryString.substring(1));
     return new URLSearchParams(queryString);
   }
+  // TODO(sof): copy constructor no longer in the spec,
+  // consider removing.
   if (init.isURLSearchParams())
     return new URLSearchParams(init.getAsURLSearchParams());
 
+  if (init.isUSVStringSequenceSequence()) {
+    return URLSearchParams::create(init.getAsUSVStringSequenceSequence(),
+                                   exceptionState);
+  }
+
   DCHECK(init.isNull());
   return new URLSearchParams(String());
 }
 
+URLSearchParams* URLSearchParams::create(const Vector<Vector<String>>& init,
+                                         ExceptionState& exceptionState) {
+  URLSearchParams* instance = new URLSearchParams(String());
+  for (unsigned i = 0; i < init.size(); ++i) {
+    const Vector<String>& pair = init[i];
+    if (pair.size() != 2) {
+      exceptionState.throwTypeError(ExceptionMessages::failedToConstruct(
+          "URLSearchParams",
+          "Sequence initializer must only contain pair elements"));
+      return nullptr;
+    }
+    instance->append(pair[0], pair[1]);

[tyoshino (SeeGerritForStatus), 2017/03/01 08:07:26]

can we populate m_params first and then runUpdateSteps() once at the end like
setInput()? this would call runUpdateSteps() every time append() is called.

[sof, 2017/03/01 08:40:59]

Done, runUpdateSteps() would be near no-op in this case.

+  }
+  return instance;
+}
+
 URLSearchParams::URLSearchParams(const String& queryString, DOMURL* urlObject)
     : m_urlObject(urlObject) {
   if (!queryString.isEmpty())