Fix crashes in Sync related to unallowed uses of sync primitives on the ThreadPool.

Bug: 1023801
Change-Id: I2db91fc9d6979fe503ee761b955cd1756bdfbddc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1912882
Auto-Submit: Oliver Li <olivierli@chromium.org>
Reviewed-by: François Doray <fdoray@chromium.org>
Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714906}

base/threading/thread_restrictions.h

@@ -214,6 +214,8 @@ class FinancialPing;
 }
 namespace syncer {
 class GetLocalChangesRequest;
+class HttpBridge;
+class ModelSafeWorker;
 }
 namespace ui {
 class CommandBufferClientImpl;
@@ -422,7 +424,9 @@ class BASE_EXPORT ScopedAllowBaseSyncPrimitives {
   friend class rlz_lib::FinancialPing;
   friend class shell_integration_linux::
       LaunchXdgUtilityScopedAllowBaseSyncPrimitives;
+  friend class syncer::HttpBridge;
   friend class syncer::GetLocalChangesRequest;
+  friend class syncer::ModelSafeWorker;
   friend class webrtc::DesktopConfigurationMonitor;
 
   // Usage that should be fixed:

components/sync/engine/model_safe_worker.cc

@@ -8,6 +8,7 @@
 
 #include "base/bind.h"
 #include "base/json/json_writer.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/values.h"
 
 namespace syncer {
@@ -115,7 +116,10 @@ SyncerError ModelSafeWorker::DoWorkAndWaitUntilDone(WorkCallback work) {
 
   // Unblocked when the task runs or is deleted or when RequestStop() is called
   // before the task starts running.
-  work_done_or_abandoned_.Wait();
+  {
+    base::ScopedAllowBaseSyncPrimitives allow_wait;
+    work_done_or_abandoned_.Wait();
+  }
 
   return did_run ? error : SyncerError(SyncerError::CANNOT_DO_WORK);
 }

components/sync/engine/net/http_bridge.cc

@@ -18,6 +18,7 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/task/post_task.h"
+#include "base/threading/thread_restrictions.h"
 #include "components/sync/base/cancelation_signal.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
@@ -199,7 +200,10 @@ bool HttpBridge::MakeSynchronousPost(int* net_error_code,
 
   // Block until network request completes or is aborted. See
   // OnURLFetchComplete and Abort.
-  http_post_completed_.Wait();
+  {
+    base::ScopedAllowBaseSyncPrimitives allow_wait;
+    http_post_completed_.Wait();
+  }
 
   base::AutoLock lock(fetch_state_lock_);
   DCHECK(fetch_state_.request_completed || fetch_state_.aborted);