Disable COM Initialization on SchedulerWorkers When COM_INIT_CHECK_HOOK_ENABLED()

This change will allow for the detection of tasks running in
TaskScheduler that fail to post their task in a COM STA Task Runner
instead.

BUG=706512
TBR=gab@chromium.org
Previously Reviewed at https://chromium-review.googlesource.com/c/549223/

Review-Url: https://codereview.chromium.org/2978253002
Cr-Original-Commit-Position: refs/heads/master@{#487625}
Committed: https://chromium.googlesource.com/chromium/src/+/122a24f59d90a1b225e00b3ab6c9fd37fd365b8f
Review-Url: https://codereview.chromium.org/2978253002
Cr-Commit-Position: refs/heads/master@{#488327}

base/task_scheduler/scheduler_worker.cc

@@ -15,6 +15,7 @@
 #if defined(OS_MACOSX)
 #include "base/mac/scoped_nsautorelease_pool.h"
 #elif defined(OS_WIN)
+#include "base/win/com_init_check_hook.h"
 #include "base/win/scoped_com_initializer.h"
 #endif
 
@@ -43,7 +44,10 @@ class SchedulerWorker::Thread : public PlatformThread::Delegate {
     // A SchedulerWorker starts out waiting for work.
     outer_->delegate_->WaitForWork(&wake_up_event_);
 
-#if defined(OS_WIN)
+    // When defined(COM_INIT_CHECK_HOOK_ENABLED), ignore
+    // SchedulerBackwardCompatibility::INIT_COM_STA to find incorrect uses of
+    // COM that should be running in a COM STA Task Runner.
+#if defined(OS_WIN) && !defined(COM_INIT_CHECK_HOOK_ENABLED)
     std::unique_ptr<win::ScopedCOMInitializer> com_initializer;
     if (outer_->backward_compatibility_ ==
         SchedulerBackwardCompatibility::INIT_COM_STA) {
@@ -210,7 +214,7 @@ SchedulerWorker::SchedulerWorker(
       priority_hint_(priority_hint),
       delegate_(std::move(delegate)),
       task_tracker_(task_tracker),
-#if defined(OS_WIN)
+#if defined(OS_WIN) && !defined(COM_INIT_CHECK_HOOK_ENABLED)
       backward_compatibility_(backward_compatibility),
 #endif
       initial_state_(initial_state) {

base/task_scheduler/scheduler_worker.h

@@ -19,6 +19,10 @@
 #include "base/time/time.h"
 #include "build/build_config.h"
 
+#if defined(OS_WIN)
+#include "base/win/com_init_check_hook.h"
+#endif
+
 namespace base {
 namespace internal {
 
@@ -195,7 +199,7 @@ class BASE_EXPORT SchedulerWorker
   const std::unique_ptr<Delegate> delegate_;
   TaskTracker* const task_tracker_;
 
-#if defined(OS_WIN)
+#if defined(OS_WIN) && !defined(COM_INIT_CHECK_HOOK_ENABLED)
   const SchedulerBackwardCompatibility backward_compatibility_;
 #endif
 

base/task_scheduler/scheduler_worker_unittest.cc

@@ -30,6 +30,8 @@
 
 #if defined(OS_WIN)
 #include <objbase.h>
+
+#include "base/win/com_init_check_hook.h"
 #endif
 
 using testing::_;
@@ -931,7 +933,13 @@ TEST(TaskSchedulerWorkerTest, BackwardCompatibilityEnabled) {
 
   // The call to CoInitializeEx() should have returned S_FALSE to indicate that
   // the COM library was already initialized on the thread.
+  // See SchedulerWorker::Thread::ThreadMain for why we expect two different
+  // results here.
+#if defined(COM_INIT_CHECK_HOOK_ENABLED)
+  EXPECT_EQ(S_OK, delegate_raw->coinitialize_hresult());
+#else
   EXPECT_EQ(S_FALSE, delegate_raw->coinitialize_hresult());
+#endif
 
   worker->JoinForTesting();
 }