Revert "Remove AMD-style module support from gin/."

This reverts commit c1ab49a.

Reason for revert: Likely the cause of
RunnerTest.Run failure in gin_unittests: Check failed: (isolate->snapshot_blob()) == nullptr.

Original change's description:
> Remove AMD-style module support from gin/.
> 
> Bug: 718047
> Change-Id: If480fff65a2e5993ed5143eede8354f890de3a3b
> Reviewed-on: https://chromium-review.googlesource.com/812172
> Commit-Queue: Yuzhu Shen <yzshen@chromium.org>
> Reviewed-by: Jochen Eisinger <jochen@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#522850}

TBR=yzshen@chromium.org,jochen@chromium.org

Change-Id: I4a6efb21dd7972994a06ddab1316fa43e5d3e060
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 718047, 793480
Reviewed-on: https://chromium-review.googlesource.com/817373
Reviewed-by: Yuzhu Shen <yzshen@chromium.org>
Commit-Queue: Yuzhu Shen <yzshen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522921}

content/shell/renderer/layout_test/layout_test_content_renderer_client.cc

@@ -30,6 +30,7 @@
 #include "content/shell/test_runner/web_test_runner.h"
 #include "content/shell/test_runner/web_view_test_proxy.h"
 #include "content/test/mock_webclipboard_impl.h"
+#include "gin/modules/module_registry.h"
 #include "media/base/audio_latency.h"
 #include "media/base/mime_util.h"
 #include "media/media_features.h"

gin/BUILD.gn

@@ -30,6 +30,15 @@ component("gin") {
     "isolate_holder.cc",
     "modules/console.cc",
     "modules/console.h",
+    "modules/file_module_provider.cc",
+    "modules/file_module_provider.h",
+    "modules/module_registry.cc",
+    "modules/module_registry.h",
+    "modules/module_registry_observer.h",
+    "modules/module_runner_delegate.cc",
+    "modules/module_runner_delegate.h",
+    "modules/timer.cc",
+    "modules/timer.h",
     "object_template_builder.cc",
     "object_template_builder.h",
     "per_context_data.cc",
@@ -122,9 +131,20 @@ executable("gin_shell") {
 source_set("gin_test") {
   testonly = true
   sources = [
+    "test/file.cc",
+    "test/file.h",
+    "test/file_runner.cc",
+    "test/file_runner.h",
+    "test/gc.cc",
+    "test/gc.h",
+    "test/gtest.cc",
+    "test/gtest.h",
     "test/v8_test.cc",
     "test/v8_test.h",
   ]
+  data = [
+    "test/expect.js",
+  ]
 
   public_deps = [
     ":gin",
@@ -149,10 +169,13 @@ test("gin_unittests") {
     "converter_unittest.cc",
     "data_object_builder_unittest.cc",
     "interceptor_unittest.cc",
+    "modules/module_registry_unittest.cc",
+    "modules/timer_unittest.cc",
     "per_context_data_unittest.cc",
     "shell/gin_shell_unittest.cc",
     "shell_runner_unittest.cc",
     "test/run_all_unittests.cc",
+    "test/run_js_tests.cc",
     "v8_isolate_memory_dump_provider_unittest.cc",
     "v8_platform_unittest.cc",
     "wrappable_unittest.cc",
@@ -168,7 +191,10 @@ test("gin_unittests") {
   configs += [ "//v8:external_startup_data" ]
 
   data = [
+    "modules/module_registry_unittests.js",
     "shell/hello_world.js",
+    "test/file_unittests.js",
+    "test/gtest_unittests.js",
     "../OWNERS",
   ]
 

gin/modules/console.cc

@@ -9,31 +9,41 @@
 #include "base/strings/string_util.h"
 #include "gin/arguments.h"
 #include "gin/converter.h"
+#include "gin/object_template_builder.h"
+#include "gin/per_isolate_data.h"
+#include "gin/public/wrapper_info.h"
+
+using v8::ObjectTemplate;
 
 namespace gin {
 
 namespace {
 
-void Log(const v8::FunctionCallbackInfo<v8::Value>& info) {
-  Arguments args(info);
+void Log(Arguments* args) {
   std::vector<std::string> messages;
-  if (!args.GetRemaining(&messages)) {
-    args.ThrowError();
+  if (!args->GetRemaining(&messages)) {
+    args->ThrowError();
     return;
   }
   printf("%s\n", base::JoinString(messages, " ").c_str());
 }
 
+WrapperInfo g_wrapper_info = { kEmbedderNativeGin };
+
 }  // namespace
 
-// static
-void Console::Register(v8::Isolate* isolate,
-                       v8::Local<v8::ObjectTemplate> templ) {
-  v8::Local<v8::FunctionTemplate> log_templ =
-      v8::FunctionTemplate::New(isolate, Log);
-  log_templ->RemovePrototype();
+const char Console::kModuleName[] = "console";
 
-  templ->Set(StringToSymbol(isolate, "log"), log_templ);
+v8::Local<v8::Value> Console::GetModule(v8::Isolate* isolate) {
+  PerIsolateData* data = PerIsolateData::From(isolate);
+  v8::Local<ObjectTemplate> templ = data->GetObjectTemplate(&g_wrapper_info);
+  if (templ.IsEmpty()) {
+    templ = ObjectTemplateBuilder(isolate)
+        .SetMethod("log", Log)
+        .Build();
+    data->SetObjectTemplate(&g_wrapper_info, templ);
+  }
+  return templ->NewInstance(isolate->GetCurrentContext()).ToLocalChecked();
 }
 
 }  // namespace gin

gin/modules/console.h

@@ -14,8 +14,8 @@ namespace gin {
 // we'd like to evolve the API to match window.console in browsers.
 class GIN_EXPORT Console {
  public:
-  static void Register(v8::Isolate* isolate,
-                       v8::Local<v8::ObjectTemplate> templ);
+  static const char kModuleName[];
+  static v8::Local<v8::Value> GetModule(v8::Isolate* isolate);
 };
 
 }  // namespace gin

gin/modules/file_module_provider.cc

@@ -0,0 +1,74 @@
+// Copyright 2013 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 "gin/modules/file_module_provider.h"
+
+#include <stddef.h>
+
+#include "base/bind.h"
+#include "base/files/file_util.h"
+#include "base/location.h"
+#include "base/single_thread_task_runner.h"
+#include "base/strings/string_split.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "gin/converter.h"
+
+namespace gin {
+
+namespace {
+
+void AttempToLoadModule(const base::WeakPtr<Runner>& runner,
+                        const std::vector<base::FilePath>& search_paths,
+                        const std::string& id) {
+  if (!runner)
+    return;
+
+  std::vector<std::string> components = base::SplitString(
+      id, "/", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
+
+  base::FilePath path;
+  for (size_t i = 0; i < components.size(); ++i) {
+    // TODO(abarth): Technically the path components can be UTF-8. We don't
+    // handle that case correctly yet.
+    path = path.AppendASCII(components[i]);
+  }
+  path = path.AddExtension(FILE_PATH_LITERAL("js"));
+
+  for (size_t i = 0; i < search_paths.size(); ++i) {
+    std::string source;
+    if (!ReadFileToString(search_paths[i].Append(path), &source))
+      continue;
+
+    Runner::Scope scope(runner.get());
+    runner->Run(source, id);
+    return;
+  }
+  LOG(ERROR) << "Failed to load module from disk: " << id;
+}
+
+}  // namespace
+
+FileModuleProvider::FileModuleProvider(
+    const std::vector<base::FilePath>& search_paths)
+    : search_paths_(search_paths) {
+}
+
+FileModuleProvider::~FileModuleProvider() = default;
+
+void FileModuleProvider::AttempToLoadModules(
+    Runner* runner, const std::set<std::string>& ids) {
+  std::set<std::string> modules = ids;
+  for (std::set<std::string>::const_iterator it = modules.begin();
+       it != modules.end(); ++it) {
+    const std::string& id = *it;
+    if (attempted_ids_.count(id))
+      continue;
+    attempted_ids_.insert(id);
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(AttempToLoadModule, runner->GetWeakPtr(),
+                              search_paths_, id));
+  }
+}
+
+}  // namespace gin

gin/modules/file_module_provider.h

@@ -0,0 +1,45 @@
+// Copyright 2013 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 GIN_MODULES_FILE_MODULE_PROVIDER_H_
+#define GIN_MODULES_FILE_MODULE_PROVIDER_H_
+
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/files/file_path.h"
+#include "base/macros.h"
+#include "gin/gin_export.h"
+#include "gin/runner.h"
+
+namespace gin {
+
+// FileModuleProvider knows how to load AMD modules off disk. It searches for
+// modules in the directories indiciated by |search_paths|. Although we still
+// read from the file system on the main thread, we'll eventually want to move
+// the reads to a background thread.
+class GIN_EXPORT FileModuleProvider {
+ public:
+  explicit FileModuleProvider(
+      const std::vector<base::FilePath>& search_paths);
+  ~FileModuleProvider();
+
+  // Searches for modules with |ids| in the file system. If found, the modules
+  // will be executed asynchronously by |runner|.
+  void AttempToLoadModules(Runner* runner, const std::set<std::string>& ids);
+
+ private:
+  std::vector<base::FilePath> search_paths_;
+
+  // We'll only search for a given module once. We remember the set of modules
+  // we've already looked for in |attempted_ids_|.
+  std::set<std::string> attempted_ids_;
+
+  DISALLOW_COPY_AND_ASSIGN(FileModuleProvider);
+};
+
+}  // namespace gin
+
+#endif  // GIN_MODULES_FILE_MODULE_PROVIDER_H_