Remove unused free function GetIOSChromeParseJSONCallback()

This function is never used except in the function unit tests.
Remove it and the corresponding unit tests.

Bug: 842655, 964232, 714018
Change-Id: Ia0e2f85dd86019db776dfed9980b4800def49580
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1627370
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662572}

ios/chrome/browser/BUILD.gn

@@ -217,7 +217,6 @@ source_set("browser_impl") {
     "//ios/chrome/browser/translate",
     "//ios/chrome/browser/ui:feature_flags",
     "//ios/chrome/browser/update_client",
-    "//ios/chrome/browser/web_resource",
     "//ios/chrome/common",
     "//ios/chrome/common/app_group",
     "//ios/public/provider/chrome/browser",

ios/chrome/browser/application_context_impl.cc

@@ -50,7 +50,6 @@
 #include "ios/chrome/browser/prefs/browser_prefs.h"
 #include "ios/chrome/browser/prefs/ios_chrome_pref_service_factory.h"
 #include "ios/chrome/browser/update_client/ios_chrome_update_query_params_delegate.h"
-#include "ios/chrome/browser/web_resource/web_resource_util.h"
 #include "ios/chrome/common/channel_info.h"
 #include "ios/web/public/web_task_traits.h"
 #include "ios/web/public/web_thread.h"

ios/chrome/browser/web_resource/BUILD.gn

-# 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.
-
-source_set("web_resource") {
-  sources = [
-    "web_resource_util.cc",
-    "web_resource_util.h",
-  ]
-  deps = [
-    "//base",
-    "//components/web_resource",
-    "//ios/web",
-  ]
-}
-
-source_set("unit_tests") {
-  testonly = true
-  sources = [
-    "web_resource_util_unittest.cc",
-  ]
-  deps = [
-    ":web_resource",
-    "//base",
-    "//base/test:test_support",
-    "//ios/web",
-    "//testing/gtest",
-  ]
-}

ios/chrome/browser/web_resource/OWNERS

-achuith@chromium.org
-rsesek@chromium.org
-
-# TEAM: ios-directory-owners@chromium.org
-# OS: iOS

ios/chrome/browser/web_resource/web_resource_util.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 "base/bind.h"
-#include "base/json/json_reader.h"
-#include "base/location.h"
-#include "base/task/post_task.h"
-#include "base/task_runner.h"
-#include "base/task_runner_util.h"
-#include "base/threading/thread_task_runner_handle.h"
-#include "base/values.h"
-
-namespace web_resource {
-
-namespace {
-
-const char kInvalidDataTypeError[] =
-    "Data from web resource server is missing or not valid JSON.";
-
-const char kUnexpectedJSONFormatError[] =
-    "Data from web resource server does not have expected format.";
-
-// Parses |data| as a JSON string and calls back on |task_runner|.
-// Must not be called on the UI thread, for performance reasons.
-void ParseJSONOnBackgroundThread(
-    base::TaskRunner* task_runner,
-    const std::string& data,
-    const WebResourceService::SuccessCallback& success_callback,
-    const WebResourceService::ErrorCallback& error_callback) {
-  if (data.empty()) {
-    task_runner->PostTask(
-        FROM_HERE, base::BindOnce(error_callback, kInvalidDataTypeError));
-    return;
-  }
-
-  base::Optional<base::Value> value(base::JSONReader::Read(data));
-  if (!value) {
-    // Page information not properly read, or corrupted.
-    task_runner->PostTask(
-        FROM_HERE, base::BindOnce(error_callback, kInvalidDataTypeError));
-    return;
-  }
-
-  if (!value->is_dict()) {
-    task_runner->PostTask(
-        FROM_HERE, base::BindOnce(error_callback, kUnexpectedJSONFormatError));
-    return;
-  }
-
-  task_runner->PostTask(FROM_HERE,
-                        base::BindOnce(success_callback, std::move(*value)));
-}
-
-// Starts the parsing of |data| as a JSON string asynchronously on a background
-// thread. Can be called from the UI thread.
-void StartParseJSONAsync(
-    const std::string& data,
-    const WebResourceService::SuccessCallback& success_callback,
-    const WebResourceService::ErrorCallback& error_callback) {
-  base::PostTaskWithTraits(
-      FROM_HERE, {base::MayBlock(), base::TaskPriority::BEST_EFFORT},
-      base::BindOnce(&ParseJSONOnBackgroundThread,
-                     base::RetainedRef(base::ThreadTaskRunnerHandle::Get()),
-                     data, success_callback, error_callback));
-}
-
-}  // namespace
-
-WebResourceService::ParseJSONCallback GetIOSChromeParseJSONCallback() {
-  return base::Bind(&StartParseJSONAsync);
-}
-
-}  // namespace web_resource

ios/chrome/browser/web_resource/web_resource_util.h

-// 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.
-
-#ifndef IOS_CHROME_BROWSER_WEB_RESOURCE_WEB_RESOURCE_UTIL_H_
-#define IOS_CHROME_BROWSER_WEB_RESOURCE_WEB_RESOURCE_UTIL_H_
-
-#include "components/web_resource/web_resource_service.h"
-
-namespace web_resource {
-
-// Returns a ParseJSONCallback that parses JSON on a background thread.
-// Generates an error if the data is not a dictionary.
-WebResourceService::ParseJSONCallback GetIOSChromeParseJSONCallback();
-
-}  // namespace web_resource
-
-#endif  // IOS_CHROME_BROWSER_WEB_RESOURCE_WEB_RESOURCE_UTIL_H_

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"
-#include "base/bind_helpers.h"
-#include "base/run_loop.h"
-#include "base/strings/stringprintf.h"
-#include "base/test/scoped_task_environment.h"
-#include "base/values.h"
-#include "ios/web/public/web_thread.h"
-#include "testing/gtest/include/gtest/gtest.h"
-#include "testing/platform_test.h"
-
-namespace web_resource {
-
-class WebResourceUtilTest : public PlatformTest {
- protected:
-  WebResourceUtilTest() : error_called_(false), success_called_(false) {}
-  ~WebResourceUtilTest() override {}
-
-  WebResourceService::SuccessCallback GetSuccessCallback() {
-    return base::Bind(&WebResourceUtilTest::OnParseSuccess,
-                      base::Unretained(this));
-  }
-
-  WebResourceService::ErrorCallback GetErrorCallback() {
-    return base::Bind(&WebResourceUtilTest::OnParseError,
-                      base::Unretained(this));
-  }
-
-  // Called on success.
-  void OnParseSuccess(base::Value value) {
-    success_called_ = true;
-    value_ = std::move(value);
-  }
-
-  // Called on error.
-  void OnParseError(const std::string& error) {
-    error_called_ = true;
-    error_ = error;
-  }
-
-  void FlushBackgroundTasks() {
-    // The function is not synchronous, callbacks are not called before flushing
-    // the tasks.
-    EXPECT_FALSE(success_called_);
-    EXPECT_FALSE(error_called_);
-
-    scoped_task_environment_.RunUntilIdle();
-  }
-
-  base::test::ScopedTaskEnvironment scoped_task_environment_;
-  std::string error_;
-  base::Optional<base::Value> value_;
-  bool error_called_;
-  bool success_called_;
-};
-
-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 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.
-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.
-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

ios/chrome/test/BUILD.gn

@@ -258,7 +258,6 @@ test("ios_chrome_unittests") {
     "//ios/chrome/browser/voice:unit_tests",
     "//ios/chrome/browser/web:unit_tests",
     "//ios/chrome/browser/web:unit_tests_internal",
-    "//ios/chrome/browser/web_resource:unit_tests",
     "//ios/chrome/browser/web_state_list:unit_tests",
     "//ios/chrome/browser/web_state_list/web_usage_enabler:unit_tests",
     "//ios/chrome/browser/webui:unit_tests",