[URL] Do not run update steps when URLSearchParam is created

See https://github.com/whatwg/url/issues/350 and
https://github.com/whatwg/url/issues/18.

Bug: 776344
Change-Id: I7881add2fc5b858874da42cef7b14a9e8ee10262
Reviewed-on: https://chromium-review.googlesource.com/756537
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Takeshi Yoshino <tyoshino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515937}

third_party/WebKit/LayoutTests/external/wpt/url/urlsearchparams-stringifier-expected.txt

-This is a testharness.js-based test.
-PASS Serialize space
-PASS Serialize empty value
-PASS Serialize empty name
-PASS Serialize empty name and value
-PASS Serialize +
-PASS Serialize =
-PASS Serialize &
-PASS Serialize *-._
-PASS Serialize %
-PASS Serialize \0
-PASS Serialize 💩
-PASS URLSearchParams.toString
-FAIL URLSearchParams connected to URL assert_equals: expected "http://www.example.com/?a=b,c" but got "http://www.example.com/?a=b%2Cc"
-Harness: the test ran to completion.
-

third_party/WebKit/Source/core/url/DOMURL.cpp

@@ -111,7 +111,7 @@ void DOMURL::UpdateSearchParams(const String& query_string) {
 #if DCHECK_IS_ON()
   DCHECK_EQ(search_params_->UrlObject(), this);
 #endif
-  search_params_->SetInput(query_string);
+  search_params_->SetInputWithoutUpdate(query_string);
 }
 
 }  // namespace blink

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

@@ -82,14 +82,13 @@ URLSearchParams* URLSearchParams::Create(const Vector<Vector<String>>& init,
     }
     instance->AppendWithoutUpdate(pair[0], pair[1]);
   }
-  instance->RunUpdateSteps();
   return instance;
 }
 
 URLSearchParams::URLSearchParams(const String& query_string, DOMURL* url_object)
     : url_object_(url_object) {
   if (!query_string.IsEmpty())
-    SetInput(query_string);
+    SetInputWithoutUpdate(query_string);
 }
 
 URLSearchParams* URLSearchParams::Create(
@@ -100,7 +99,6 @@ URLSearchParams* URLSearchParams::Create(
     return instance;
   for (const auto& item : init)
     instance->AppendWithoutUpdate(item.first, item.second);
-  instance->RunUpdateSteps();
   return instance;
 }
 
@@ -131,7 +129,7 @@ static String DecodeString(String input) {
   return DecodeURLEscapeSequences(input.Replace('+', ' '));
 }
 
-void URLSearchParams::SetInput(const String& query_string) {
+void URLSearchParams::SetInputWithoutUpdate(const String& query_string) {
   params_.clear();
 
   size_t start = 0;
@@ -157,7 +155,6 @@ void URLSearchParams::SetInput(const String& query_string) {
     }
     start = name_value_end + 1;
   }
-  RunUpdateSteps();
 }
 
 String URLSearchParams::toString() const {

third_party/WebKit/Source/core/url/URLSearchParams.h

@@ -50,7 +50,7 @@ class CORE_EXPORT URLSearchParams final : public ScriptWrappable,
   bool has(const String&) const;
   void set(const String& name, const String& value);
   void sort();
-  void SetInput(const String&);
+  void SetInputWithoutUpdate(const String&);
 
   // Internal helpers
   scoped_refptr<EncodedFormData> ToEncodedFormData() const;