ServiceWorker: Move OnScriptLoaded to the right place

This is 6th patch of script streaming project split off from
https://chromium-review.googlesource.com/c/538477.

This patch:
 - Moves where OnScriptLoaded() is called to after calling
   InstalledScriptsManager::GetScriptData when script streaming is enabled.
 - Changes to use StringBuilder in ServiceWorker in
   ServiceWorkerInstalledScriptsManager.

The script streaming TRACE_EVENT is broken by this patch. I'll fix it in the
following patch (https://crrev.com/c/566783).

Bug: 683037
Change-Id: Ice19b90bf32d007c8a25993b207f6eb5088047a7
Reviewed-on: https://chromium-review.googlesource.com/566781Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487404}

content/renderer/service_worker/service_worker_context_client.cc

@@ -689,9 +689,6 @@ void ServiceWorkerContextClient::WorkerContextFailedToStart() {
 }
 
 void ServiceWorkerContextClient::WorkerScriptLoaded() {
-  DCHECK(main_thread_task_runner_->RunsTasksInCurrentSequence());
-  DCHECK(!proxy_);
-
   (*instance_host_)->OnScriptLoaded();
 }
 

content/renderer/service_worker/service_worker_context_client.h

@@ -128,9 +128,8 @@ class ServiceWorkerContextClient : public blink::WebServiceWorkerContextClient,
 
   // Called on the main thread.
   void WorkerContextFailedToStart() override;
-  void WorkerScriptLoaded() override;
   bool HasAssociatedRegistration() override;
-
+  void WorkerScriptLoaded() override;
   void WorkerContextStarted(
       blink::WebServiceWorkerContextProxy* proxy) override;
   void DidEvaluateWorkerScript(bool success) override;

third_party/WebKit/Source/core/workers/WorkerReportingProxy.h

@@ -59,26 +59,32 @@ class CORE_EXPORT WorkerReportingProxy {
                                     SourceLocation*) {}
   virtual void PostMessageToPageInspector(int session_id, const String&) {}
 
-  // Invoked when the new WorkerGlobalScope is created. This is called after
-  // didLoadWorkerScript().
+  // Invoked when the new WorkerGlobalScope is created on
+  // WorkerThread::InitializeOnWorkerThread.
   virtual void DidCreateWorkerGlobalScope(WorkerOrWorkletGlobalScope*) {}
 
-  // Invoked when the WorkerGlobalScope is initialized. This is called after
-  // didCreateWorkerGlobalScope().
+  // Invoked when the WorkerGlobalScope is initialized on
+  // WorkerThread::InitializeOnWorkerThread.
   virtual void DidInitializeWorkerContext() {}
 
-  // Invoked when the worker script is about to be evaluated. This is called
-  // after didInitializeWorkerContext().
+  // Invoked when the worker's main script is loaded on
+  // WorkerThread::InitializeOnWorkerThread. Only invoked when the script was
+  // loaded on the worker thread, i.e., via InstalledScriptsManager rather than
+  // via ResourceLoader.
+  virtual void DidLoadInstalledScript() {}
+
+  // Invoked when the worker script is about to be evaluated on
+  // WorkerThread::InitializeOnWorkerThread.
   virtual void WillEvaluateWorkerScript(size_t script_size,
                                         size_t cached_metadata_size) {}
 
-  // Invoked when an imported script is about to be evaluated. This is called
-  // after willEvaluateWorkerScript().
+  // Invoked when an imported script is about to be evaluated.
   virtual void WillEvaluateImportedScript(size_t script_size,
                                           size_t cached_metadata_size) {}
 
-  // Invoked when the worker script is evaluated. |success| is true if the
-  // evaluation completed with no uncaught exception.
+  // Invoked when the worker script is evaluated on
+  // WorkerThread::InitializeOnWorkerThread. |success| is true if the evaluation
+  // completed with no uncaught exception.
   virtual void DidEvaluateWorkerScript(bool success) {}
 
   // Invoked when close() is invoked on the worker context.

third_party/WebKit/Source/core/workers/WorkerThread.cpp

@@ -453,12 +453,15 @@ void WorkerThread::InitializeOnWorkerThread(
     // OriginTrialTokens to |startup_data|.
     // TODO(shimazu): Add a post task to the main thread for setting
     // ContentSecurityPolicy and ReferrerPolicy.
+
+    // GetScriptData blocks until the script is received from the browser.
     auto script_data = GetInstalledScriptsManager()->GetScriptData(script_url);
     DCHECK(script_data);
     DCHECK(source_code.IsEmpty());
     DCHECK(!cached_meta_data);
     source_code = std::move(script_data->source_text);
     cached_meta_data = std::move(script_data->meta_data);
+    worker_reporting_proxy_.DidLoadInstalledScript();
   } else {
     source_code = std::move(given_source_code);
     cached_meta_data = std::move(given_cached_meta_data);

third_party/WebKit/Source/modules/exported/WebEmbeddedWorkerImpl.cpp

@@ -343,16 +343,10 @@ void WebEmbeddedWorkerImpl::DidFinishDocumentLoad() {
   // Kickstart the worker before loading the script when the script has been
   // installed.
   if (RuntimeEnabledFeatures::ServiceWorkerScriptStreamingEnabled() &&
+      installed_scripts_manager_ &&
       installed_scripts_manager_->IsScriptInstalled(
           worker_start_data_.script_url)) {
-    // TODO(shimazu): Move WorkerScriptLoaded to the correct place which is
-    // after InstalledScriptsManager::GetScriptData() called at
-    // WorkerThread::InitializeOnWorkerThread().
-    worker_context_client_->WorkerScriptLoaded();
-    if (pause_after_download_state_ == kDoPauseAfterDownload) {
-      pause_after_download_state_ = kIsPausedAfterDownload;
-      return;
-    }
+    DCHECK_EQ(pause_after_download_state_, kDontPauseAfterDownload);
     StartWorkerThread();
     return;
   }

third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerGlobalScopeProxy.cpp

@@ -545,6 +545,10 @@ void ServiceWorkerGlobalScopeProxy::DidInitializeWorkerContext() {
       WorkerGlobalScope()->ScriptController()->GetContext());
 }
 
+void ServiceWorkerGlobalScopeProxy::DidLoadInstalledScript() {
+  Client().WorkerScriptLoaded();
+}
+
 void ServiceWorkerGlobalScopeProxy::WillEvaluateWorkerScript(
     size_t script_size,
     size_t cached_metadata_size) {

third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerGlobalScopeProxy.h

@@ -150,6 +150,7 @@ class ServiceWorkerGlobalScopeProxy final
   void PostMessageToPageInspector(int session_id, const String&) override;
   void DidCreateWorkerGlobalScope(WorkerOrWorkletGlobalScope*) override;
   void DidInitializeWorkerContext() override;
+  void DidLoadInstalledScript() override;
   void WillEvaluateWorkerScript(size_t script_size,
                                 size_t cached_metadata_size) override;
   void WillEvaluateImportedScript(size_t script_size,

third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerInstalledScriptsManager.cpp

@@ -6,12 +6,15 @@
 
 #include "core/html/parser/TextResourceDecoder.h"
 #include "modules/serviceworkers/ServiceWorkerThread.h"
+#include "platform/wtf/text/StringBuilder.h"
 
 namespace blink {
 
 ServiceWorkerInstalledScriptsManager::ServiceWorkerInstalledScriptsManager(
     std::unique_ptr<WebServiceWorkerInstalledScriptsManager> manager)
-    : manager_(std::move(manager)) {}
+    : manager_(std::move(manager)) {
+  DCHECK(manager_);
+}
 
 bool ServiceWorkerInstalledScriptsManager::IsScriptInstalled(
     const KURL& script_url) const {
@@ -24,7 +27,6 @@ ServiceWorkerInstalledScriptsManager::GetScriptData(const KURL& script_url) {
   // This blocks until the script is received from the browser.
   std::unique_ptr<WebServiceWorkerInstalledScriptsManager::RawScriptData>
       raw_script_data = manager_->GetRawScriptData(script_url);
-
   if (!raw_script_data)
     return WTF::nullopt;
 
@@ -42,9 +44,11 @@ ServiceWorkerInstalledScriptsManager::GetScriptData(const KURL& script_url) {
   InstalledScriptsManager::ScriptData script_data;
   // TODO(shimazu): Read the headers for ContentSecurityPolicy, ReferrerPolicy,
   // and OriginTrialTokens and set them to |script_data|.
-  for (const auto& chunk : raw_script_data->ScriptTextChunks()) {
-    script_data.source_text.append(decoder->Decode(chunk.Data(), chunk.size()));
-  }
+  StringBuilder source_text_builder;
+  for (const auto& chunk : raw_script_data->ScriptTextChunks())
+    source_text_builder.Append(decoder->Decode(chunk.Data(), chunk.size()));
+  script_data.source_text = source_text_builder.ToString();
+
   if (raw_script_data->MetaDataChunks().size() > 0) {
     size_t total_metadata_size = 0;
     for (const auto& chunk : raw_script_data->MetaDataChunks())
@@ -54,6 +58,7 @@ ServiceWorkerInstalledScriptsManager::GetScriptData(const KURL& script_url) {
     for (const auto& chunk : raw_script_data->MetaDataChunks())
       script_data.meta_data->Append(chunk.Data(), chunk.size());
   }
+
   script_data.headers.Adopt(raw_script_data->TakeHeaders());
   return Optional<ScriptData>(std::move(script_data));
 }

third_party/WebKit/public/web/modules/serviceworker/WebServiceWorkerContextClient.h

@@ -73,7 +73,9 @@ class WebServiceWorkerContextClient {
   virtual void WorkerReadyForInspection() {}
 
   // The worker script is successfully loaded and a new thread is about to
-  // be started. Called on the main thread.
+  // be started. Called on the main thread when the script is served from
+  // ResourceLoader or on the worker thread when the script is served via
+  // WebServiceWorkerInstalledScriptsManager.
   virtual void WorkerScriptLoaded() {}
 
   virtual bool HasAssociatedRegistration() { return false; }