Revert "[SendTabToSelf] Don't show send tab to self entry points when sync is paused"

This reverts commit 6b3b1630.

Reason for revert:
The test crashes in official Linux builds and UBSan-vptr builds,
see second bug below.

Original change's description:
> [SendTabToSelf] Don't show send tab to self entry points when sync is paused
> 
> Bug: 950642
> Change-Id: I772378ceaa7e4d43fce185a8e8d251325483788b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1573158
> Commit-Queue: Tina Wang <tinazwang@chromium.org>
> Reviewed-by: sebsg <sebsg@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#655805}

TBR=sebsg@chromium.org,tgupta@chromium.org,tinazwang@chromium.org

Change-Id: I9776016673244e9da2c2219452f3b5b0a2a836df
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 950642, 958738
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1591927Reviewed-by: Hans Wennborg <hans@chromium.org>
Commit-Queue: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#655946}

chrome/browser/send_tab_to_self/send_tab_to_self_util.cc

@@ -14,7 +14,6 @@
 #include "components/sync/device_info/device_info.h"
 #include "components/sync/device_info/device_info_sync_service.h"
 #include "components/sync/device_info/device_info_tracker.h"
-#include "components/sync/driver/profile_sync_service.h"
 #include "components/sync/driver/sync_driver_switches.h"
 #include "components/sync/driver/sync_service.h"
 #include "components/sync/driver/sync_user_settings.h"
@@ -34,13 +33,6 @@ bool IsSendingEnabled() {
          base::FeatureList::IsEnabled(kSendTabToSelfShowSendingUI);
 }
 
-bool IsSyncPaused(Profile* profile) {
-  syncer::ProfileSyncService* service =
-      ProfileSyncServiceFactory::GetAsProfileSyncServiceForProfile(profile);
-  return service->GetDisableReasons() ==
-         syncer::SyncService::DISABLE_REASON_PAUSED;
-}
-
 bool IsUserSyncTypeActive(Profile* profile) {
   SendTabToSelfSyncService* service =
       SendTabToSelfSyncServiceFactory::GetForProfile(profile);
@@ -58,12 +50,6 @@ bool IsSyncingOnMultipleDevices(Profile* profile) {
          device_sync_service->GetDeviceInfoTracker()->CountActiveDevices() > 1;
 }
 
-bool IsSettingRequirementsMet(Profile* profile) {
-  // If sending is enabled, then so is receiving.
-  return IsSendingEnabled() && !IsSyncPaused(profile) &&
-         IsUserSyncTypeActive(profile) && IsSyncingOnMultipleDevices(profile);
-}
-
 bool IsContentRequirementsMet(const GURL& url, Profile* profile) {
   bool is_http_or_https = url.SchemeIsHTTPOrHTTPS();
   bool is_native_page = url.SchemeIs(content::kChromeUIScheme);
@@ -79,7 +65,9 @@ bool ShouldOfferFeature(content::WebContents* web_contents) {
   Profile* profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
 
-  return IsSettingRequirementsMet(profile) &&
+  // If sending is enabled, then so is receiving.
+  return IsSendingEnabled() && IsUserSyncTypeActive(profile) &&
+         IsSyncingOnMultipleDevices(profile) &&
          IsContentRequirementsMet(web_contents->GetURL(), profile);
 }
 
@@ -89,7 +77,8 @@ bool ShouldOfferFeatureForLink(content::WebContents* web_contents,
     return false;
   Profile* profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
-  return IsSettingRequirementsMet(profile) &&
+  return IsSendingEnabled() && IsUserSyncTypeActive(profile) &&
+         IsSyncingOnMultipleDevices(profile) &&
          (IsContentRequirementsMet(web_contents->GetURL(), profile) ||
           IsContentRequirementsMet(link_url, profile));
 }

chrome/browser/send_tab_to_self/send_tab_to_self_util.h

@@ -21,18 +21,12 @@ bool IsReceivingEnabled();
 // flags are enabled.
 bool IsSendingEnabled();
 
-// Return true if the the sync mode is paused.
-bool IsSyncPaused(Profile* profile);
-
 // Returns true if the SendTabToSelf sync datatype is active.
 bool IsUserSyncTypeActive(Profile* profile);
 
 // Returns true if the user syncing on two or more devices.
 bool IsSyncingOnMultipleDevices(Profile* profile);
 
-// Returns true if the flag and sync setting requirements are met.
-bool IsSettingRequirementsMet(Profile* profile);
-
 // Returns true if the tab and web content requirements are met:
 //  User is viewing an HTTP or HTTPS page.
 //  User is not on a native page.

chrome/browser/send_tab_to_self/send_tab_to_self_util_unittest.cc

@@ -185,14 +185,6 @@ TEST_F(SendTabToSelfUtilTest, IsOnlySendingEnabled_False) {
   EXPECT_FALSE(IsReceivingEnabled());
 }
 
-TEST_F(SendTabToSelfUtilTest, IsSyncPaused) {
-  EXPECT_FALSE(IsSyncPaused(profile()));
-
-  test_sync_service_->SetDisableReasons(
-      syncer::SyncService::DISABLE_REASON_PAUSED);
-  EXPECT_TRUE(IsSyncPaused(profile()));
-}
-
 TEST_F(SendTabToSelfUtilTest, IsSyncingOnMultipleDevices_True) {
   mock_device_sync_service_->SetTrackerActiveDevices(2);