[Background Fetch] Create a feature flag for uploads.

Bug: 774054
Change-Id: I42ce8c29699701aec0df0de806ca5077bf49a056
Reviewed-on: https://chromium-review.googlesource.com/c/1297144Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602407}

content/child/runtime_features.cc

@@ -495,6 +495,9 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
   if (!base::FeatureList::IsEnabled(features::kBackgroundFetch))
     WebRuntimeFeatures::EnableBackgroundFetch(false);
 
+  WebRuntimeFeatures::EnableBackgroundFetchUploads(
+      base::FeatureList::IsEnabled(features::kBackgroundFetchUploads));
+
   WebRuntimeFeatures::EnableNoHoverAfterLayoutChange(
       base::FeatureList::IsEnabled(features::kNoHoverAfterLayoutChange));
 

content/public/common/content_features.cc

@@ -53,6 +53,10 @@ const base::Feature kAwaitOptimization{"AwaitOptimization",
 const base::Feature kBackgroundFetch{"BackgroundFetch",
                                      base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Enables using uploads in a Background Fetch.
+const base::Feature kBackgroundFetchUploads{"BackgroundFetchUploads",
+                                            base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Enable incremental marking for Blink's heap managed by the Oilpan garbage
 // collector.
 const base::Feature kBlinkHeapIncrementalMarking{

content/public/common/content_features.h

@@ -26,6 +26,7 @@ CONTENT_EXPORT extern const base::Feature kAudioServiceLaunchOnStartup;
 CONTENT_EXPORT extern const base::Feature kAudioServiceOutOfProcess;
 CONTENT_EXPORT extern const base::Feature kAwaitOptimization;
 CONTENT_EXPORT extern const base::Feature kBackgroundFetch;
+CONTENT_EXPORT extern const base::Feature kBackgroundFetchUploads;
 CONTENT_EXPORT extern const base::Feature kBlinkHeapIncrementalMarking;
 CONTENT_EXPORT extern const base::Feature kBlinkHeapUnifiedGarbageCollection;
 CONTENT_EXPORT extern const base::Feature kBloatedRendererDetection;

third_party/blink/public/platform/web_runtime_features.h

@@ -80,6 +80,7 @@ class WebRuntimeFeatures {
   BLINK_PLATFORM_EXPORT static void EnableAllowActivationDelegationAttr(bool);
   BLINK_PLATFORM_EXPORT static void EnableAudioOutputDevices(bool);
   BLINK_PLATFORM_EXPORT static void EnableBackgroundFetch(bool);
+  BLINK_PLATFORM_EXPORT static void EnableBackgroundFetchUploads(bool);
   BLINK_PLATFORM_EXPORT static void EnableBlinkHeapIncrementalMarking(bool);
   BLINK_PLATFORM_EXPORT static void EnableBlinkHeapUnifiedGarbageCollection(
       bool);

third_party/blink/renderer/modules/background_fetch/background_fetch_manager.cc

@@ -150,8 +150,8 @@ ScriptPromise BackgroundFetchManager::fetch(
   UMA_HISTOGRAM_BOOLEAN("BackgroundFetch.HasRequestsWithBody",
                         has_requests_with_body);
 
-  // TODO(crbug.com/789854): Stop bailing here once we support uploads.
-  if (has_requests_with_body) {
+  if (has_requests_with_body &&
+      !RuntimeEnabledFeatures::BackgroundFetchUploadsEnabled()) {
     return ScriptPromise::Reject(
         script_state, V8ThrowException::CreateTypeError(
                           script_state->GetIsolate(),

third_party/blink/renderer/platform/exported/web_runtime_features.cc

@@ -572,4 +572,8 @@ void WebRuntimeFeatures::EnableBackgroundFetch(bool enable) {
   RuntimeEnabledFeatures::SetBackgroundFetchEnabled(enable);
 }
 
+void WebRuntimeFeatures::EnableBackgroundFetchUploads(bool enable) {
+  RuntimeEnabledFeatures::SetBackgroundFetchUploadsEnabled(enable);
+}
+
 }  // namespace blink

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -117,6 +117,10 @@
       origin_trial_feature_name: "BackgroundFetch",
       status: "experimental",
     },
+    {
+      name: "BackgroundFetchUploads",
+      status: "experimental",
+    },
     {
       name: "BackgroundVideoTrackOptimization",
       status: "stable",