Add base::Feature for AppCache (default on)

This is to enable developers to turn it off for testing what future
deprecation will look like.

Bug: 582750,1055010
Change-Id: I7ea0570ec6cda99ec8027219ba5f272d875b679c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2124237
Commit-Queue: enne <enne@chromium.org>
Reviewed-by: Tao Bai <michaelbai@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755426}

android_webview/browser/aw_settings.cc

@@ -409,7 +409,8 @@ void AwSettings::PopulateWebPreferencesLocked(JNIEnv* env,
   web_prefs->plugins_enabled = false;
 
   web_prefs->application_cache_enabled =
-      Java_AwSettings_getAppCacheEnabledLocked(env, obj);
+      Java_AwSettings_getAppCacheEnabledLocked(env, obj) &&
+      content::StoragePartition::IsAppCacheEnabled();
 
   web_prefs->local_storage_enabled =
       Java_AwSettings_getDomStorageEnabledLocked(env, obj);

content/browser/renderer_host/render_view_host_impl.cc

@@ -82,6 +82,7 @@
 #include "net/base/url_util.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "services/network/public/cpp/features.h"
+#include "third_party/blink/public/common/features.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/device_form_factor.h"
@@ -487,7 +488,8 @@ const WebPreferences RenderViewHostImpl::ComputeWebPreferences() {
 
   prefs.remote_fonts_enabled =
       !command_line.HasSwitch(switches::kDisableRemoteFonts);
-  prefs.application_cache_enabled = true;
+  prefs.application_cache_enabled =
+      base::FeatureList::IsEnabled(blink::features::kAppCache);
   prefs.local_storage_enabled =
       !command_line.HasSwitch(switches::kDisableLocalStorage);
   prefs.databases_enabled =

content/browser/storage_partition_impl.cc

@@ -102,6 +102,7 @@
 #include "storage/browser/database/database_tracker.h"
 #include "storage/browser/quota/quota_manager.h"
 #include "storage/browser/quota/quota_settings.h"
+#include "third_party/blink/public/common/features.h"
 #include "third_party/blink/public/mojom/quota/quota_types.mojom.h"
 
 #if defined(OS_ANDROID)
@@ -2694,4 +2695,8 @@ void StoragePartition::SetDefaultQuotaSettingsForTesting(
   g_test_quota_settings = settings;
 }
 
+bool StoragePartition::IsAppCacheEnabled() {
+  return base::FeatureList::IsEnabled(blink::features::kAppCache);
+}
+
 }  // namespace content

content/browser/worker_host/shared_worker_service_impl.cc

@@ -36,6 +36,7 @@
 #include "content/public/common/content_switches.h"
 #include "mojo/public/cpp/bindings/remote.h"
 #include "services/network/public/mojom/fetch_api.mojom.h"
+#include "third_party/blink/public/common/features.h"
 #include "third_party/blink/public/common/messaging/message_port_channel.h"
 #include "third_party/blink/public/mojom/loader/fetch_client_settings_object.mojom.h"
 #include "third_party/blink/public/mojom/script/script_type.mojom.h"
@@ -293,11 +294,13 @@ SharedWorkerHost* SharedWorkerServiceImpl::CreateWorker(
   DCHECK(insertion_result.second);
   SharedWorkerHost* host = insertion_result.first->get();
 
-  auto appcache_handle = std::make_unique<AppCacheNavigationHandle>(
-      appcache_service_.get(), worker_process_host->GetID());
-  base::WeakPtr<AppCacheHost> appcache_host =
-      appcache_handle->host()->GetWeakPtr();
-  host->SetAppCacheHandle(std::move(appcache_handle));
+  base::WeakPtr<AppCacheHost> appcache_host;
+  if (base::FeatureList::IsEnabled(blink::features::kAppCache)) {
+    auto appcache_handle = std::make_unique<AppCacheNavigationHandle>(
+        appcache_service_.get(), worker_process_host->GetID());
+    appcache_host = appcache_handle->host()->GetWeakPtr();
+    host->SetAppCacheHandle(std::move(appcache_handle));
+  }
 
   auto service_worker_handle =
       std::make_unique<ServiceWorkerMainResourceHandle>(

content/child/runtime_features.cc

@@ -341,6 +341,7 @@ void SetRuntimeFeaturesFromChromiumFeatures() {
           {"AllowContentInitiatedDataUrlNavigations",
            features::kAllowContentInitiatedDataUrlNavigations,
            kUseFeatureState},
+          {"AppCache", blink::features::kAppCache, kDisableOnly},
           {"AudioWorkletRealtimeThread",
            blink::features::kAudioWorkletRealtimeThread, kEnableOnly},
           {"BlockCredentialedSubresources",

content/public/browser/storage_partition.h

@@ -272,6 +272,8 @@ class CONTENT_EXPORT StoragePartition {
   static void SetDefaultQuotaSettingsForTesting(
       const storage::QuotaSettings* settings);
 
+  static bool IsAppCacheEnabled();
+
  protected:
   virtual ~StoragePartition() {}
 };

third_party/blink/common/features.cc

@@ -494,5 +494,7 @@ const base::Feature kFlexNG{"FlexNG", base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kKeepScriptResourceAlive{"KeepScriptResourceAlive",
                                              base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kAppCache{"AppCache", base::FEATURE_ENABLED_BY_DEFAULT};
+
 }  // namespace features
 }  // namespace blink

third_party/blink/public/common/features.h

@@ -165,6 +165,8 @@ BLINK_COMMON_EXPORT extern const base::Feature kFlexNG;
 
 BLINK_COMMON_EXPORT extern const base::Feature kKeepScriptResourceAlive;
 
+BLINK_COMMON_EXPORT extern const base::Feature kAppCache;
+
 }  // namespace features
 }  // namespace blink
 

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -159,6 +159,7 @@
       status: "experimental",
     },
     {
+      // Enabled when blink::features::kAppCache is enabled.
       name: "AppCache",
       status: "stable",
     },