Revert of [ios] Disable WebResourceUtilTest due to risk of timeouts.

ios/chrome/browser/web_resource/web_resource_util_unittest.cc

 // 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 "ios/chrome/browser/web_resource/web_resource_util.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 43 matching lines @@
     scoped_task_environment_.RunUntilIdle();
   }
 
   base::test::ScopedTaskEnvironment scoped_task_environment_;
   std::string error_;
   std::unique_ptr<base::Value> value_;
   bool error_called_;
   bool success_called_;
 };
 
-// TODO(crbug.com/728216): Disabled because
-// ScopedTaskEnvironment::RunUntilIdle() may hang.
-TEST_F(WebResourceUtilTest, DISABLED_Success) {
+TEST_F(WebResourceUtilTest, Success) {
   const std::string kExpectedKey("foo");
   const std::string kExpectedValue("bar");
   std::string json = base::StringPrintf("{\"%s\":\"%s\"}", kExpectedKey.c_str(),
                                         kExpectedValue.c_str());
   GetIOSChromeParseJSONCallback().Run(json, GetSuccessCallback(),
                                       GetErrorCallback());
 
   FlushBackgroundTasks();
 
   // The success callback is called with the reference value.
   EXPECT_FALSE(error_called_);
   EXPECT_TRUE(success_called_);
 
   base::DictionaryValue* dictionary = nullptr;
   ASSERT_TRUE(value_->GetAsDictionary(&dictionary));
   EXPECT_EQ(1u, dictionary->size());
   base::Value* actual_value = nullptr;
   ASSERT_TRUE(dictionary->Get(kExpectedKey, &actual_value));
   std::string actual_value_as_string;
   EXPECT_TRUE(actual_value->GetAsString(&actual_value_as_string));
   EXPECT_EQ(kExpectedValue, actual_value_as_string);
 }
 
-// Only DictionaryValues are expected.
-// TODO(crbug.com/728216): Disabled because
-// ScopedTaskEnvironment::RunUntilIdle() may hang.
-TEST_F(WebResourceUtilTest, DISABLED_UnexpectedValue) {
+// Only DictionartValues are expected.
+TEST_F(WebResourceUtilTest, UnexpectedValue) {
   GetIOSChromeParseJSONCallback().Run("foo", GetSuccessCallback(),
                                       GetErrorCallback());
 
   FlushBackgroundTasks();
 
   // The error callback is called.
   EXPECT_TRUE(error_called_);
   EXPECT_FALSE(success_called_);
   EXPECT_FALSE(error_.empty());
 }
 
 // Empty data is not expected.
-// TODO(crbug.com/728216): Disabled because
-// ScopedTaskEnvironment::RunUntilIdle() may hang.
-TEST_F(WebResourceUtilTest, DISABLED_EmptyValue) {
+TEST_F(WebResourceUtilTest, EmptyValue) {
   GetIOSChromeParseJSONCallback().Run(std::string(), GetSuccessCallback(),
                                       GetErrorCallback());
 
   FlushBackgroundTasks();
 
   // The error callback is called.
   EXPECT_TRUE(error_called_);
   EXPECT_FALSE(success_called_);
   EXPECT_FALSE(error_.empty());
 }
 
 // Wrong syntax.
-// TODO(crbug.com/728216): Disabled because
-// ScopedTaskEnvironment::RunUntilIdle() may hang.
-TEST_F(WebResourceUtilTest, DISABLED_SyntaxError) {
+TEST_F(WebResourceUtilTest, SyntaxError) {
   GetIOSChromeParseJSONCallback().Run("%$[", GetSuccessCallback(),
                                       GetErrorCallback());
 
   FlushBackgroundTasks();
 
   // The error callback is called.
   EXPECT_TRUE(error_called_);
   EXPECT_FALSE(success_called_);
   EXPECT_FALSE(error_.empty());
 }
 
 }  // namespace web_resource