Revert "WebView: Ignore permanent-consistency experiments"

This reverts commit ef70c85e.

Reason for revert: WebView now supports permanent-consistency.

BUG=866722

Original change's description:
> WebView: Ignore permanent-consistency experiments
> 
> Android WebView currently treats permanent-consistency experiments
> (which are intended to retain their group assignments across runs) as
> session-consistency (which are intended to be randomly assigned on each
> run). It's safer to not apply permanent-consistency experiments to
> WebView at all, to avoid mistakes.
> 
> BUG=866722
> 
> Change-Id: I9d501437718d934c2a59b95335c787302ce758e7
> Reviewed-on: https://chromium-review.googlesource.com/1148991
> Reviewed-by: Changwan Ryu <changwan@chromium.org>
> Reviewed-by: Steven Holte <holte@chromium.org>
> Commit-Queue: Paul Miller <paulmiller@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#578070}

TBR=changwan@chromium.org,holte@chromium.org,paulmiller@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 866722
Change-Id: Ifd00450fbba1afc1db619109cf918ef75cbcf84f
Reviewed-on: https://chromium-review.googlesource.com/1237244Reviewed-by: Paul Miller <paulmiller@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Paul Miller <paulmiller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594491}

android_webview/browser/aw_variations_service_client.cc

@@ -54,10 +54,6 @@ Channel AwVariationsServiceClient::GetChannel() {
   return android_webview::GetChannelOrStable();
 }
 
-bool AwVariationsServiceClient::GetSupportsPermanentConsistency() {
-  return false;
-}
-
 bool AwVariationsServiceClient::OverridesRestrictParameter(
     std::string* parameter) {
   return false;

android_webview/browser/aw_variations_service_client.h

@@ -31,7 +31,6 @@ class AwVariationsServiceClient : public variations::VariationsServiceClient {
   scoped_refptr<network::SharedURLLoaderFactory> GetURLLoaderFactory() override;
   network_time::NetworkTimeTracker* GetNetworkTimeTracker() override;
   version_info::Channel GetChannel() override;
-  bool GetSupportsPermanentConsistency() override;
   bool OverridesRestrictParameter(std::string* parameter) override;
 
   DISALLOW_COPY_AND_ASSIGN(AwVariationsServiceClient);

components/variations/client_filterable_state.h

@@ -47,11 +47,6 @@ struct ClientFilterableState {
   // Based on base::SysInfo::IsLowEndDevice().
   bool is_low_end_device = false;
 
-  // Whether this platform supports experiments which retain their group
-  // assignments across runs.
-  // TODO(paulmiller): Remove this once https://crbug.com/866722 is resolved.
-  bool supports_permanent_consistency = true;
-
   // The country code to use for studies configured with session consistency.
   std::string session_consistency_country;
 

components/variations/service/BUILD.gn

@@ -12,7 +12,6 @@ static_library("service") {
     "variations_field_trial_creator.h",
     "variations_service.cc",
     "variations_service.h",
-    "variations_service_client.cc",
     "variations_service_client.h",
   ]
 

components/variations/service/variations_field_trial_creator.cc

@@ -259,8 +259,6 @@ VariationsFieldTrialCreator::GetClientFilterableStateForVersion(
   // evaluated, that field trial would not be able to apply for this case.
   state->is_low_end_device = base::SysInfo::IsLowEndDevice();
 #endif
-  state->supports_permanent_consistency =
-      client_->GetSupportsPermanentConsistency();
   state->session_consistency_country = GetLatestCountry();
   state->permanent_consistency_country = LoadPermanentConsistencyCountry(
       version, state->session_consistency_country);

components/variations/service/variations_service_client.cc

-// Copyright 2018 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 "components/variations/service/variations_service_client.h"
-
-namespace variations {
-
-bool VariationsServiceClient::GetSupportsPermanentConsistency() {
-  return true;
-}
-
-}  // namespace variations

components/variations/service/variations_service_client.h

@@ -45,11 +45,6 @@ class VariationsServiceClient {
   // Gets the channel of the embedder.
   virtual version_info::Channel GetChannel() = 0;
 
-  // Gets whether this platform supports experiments which retain their group
-  // assignments across runs.
-  // TODO(paulmiller): Remove this once https://crbug.com/866722 is resolved.
-  virtual bool GetSupportsPermanentConsistency();
-
   // Returns whether the embedder overrides the value of the restrict parameter.
   // |parameter| is an out-param that will contain the value of the restrict
   // parameter if true is returned.

components/variations/study_filtering.cc

@@ -12,7 +12,6 @@
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "components/variations/client_filterable_state.h"
-#include "components/variations/proto/study.pb.h"
 
 namespace variations {
 namespace {
@@ -267,14 +266,6 @@ bool ShouldAddStudy(const Study& study,
     }
   }
 
-  // TODO(paulmiller): Remove this once https://crbug.com/866722 is resolved.
-  if (study.consistency() == Study_Consistency_PERMANENT &&
-      !client_state.supports_permanent_consistency) {
-    DVLOG(1) << "Filtered out study " << study.name()
-             << " due to supports_permanent_consistency.";
-    return false;
-  }
-
   DVLOG(1) << "Kept study " << study.name() << ".";
   return true;
 }