Move the AV Check to the COM STA Task Runner

Previously, this ran in the Task Scheduler shared worker pool and
initialized an STA on its own, which blocks initializing the shared
worker pool as an MTA.

This change moves the work to the shared COM STA task runner as 
CLSID_WSCProductList expects to be run in an STA. CLSID_WbemLocator
is fine with an STA or MTA.

BUG=706479

Change-Id: I834b0fbcda47ea0168f0ce48c5ab3191adbf7f5e
Reviewed-on: https://chromium-review.googlesource.com/745317
Commit-Queue: Robert Liao <robliao@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512882}

chrome/browser/metrics/antivirus_metrics_provider_win.cc

@@ -27,9 +27,11 @@
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
+#include "base/task_runner_util.h"
 #include "base/task_scheduler/post_task.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/version.h"
+#include "base/win/com_init_util.h"
 #include "base/win/scoped_bstr.h"
 #include "base/win/scoped_com_initializer.h"
 #include "base/win/scoped_variant.h"
@@ -161,18 +163,26 @@ void AntiVirusMetricsProvider::ProvideSystemProfileMetrics(
 }
 
 void AntiVirusMetricsProvider::AsyncInit(const base::Closure& done_callback) {
-  base::PostTaskWithTraitsAndReplyWithResult(
+  // __uuidof(WSCProductList) expects to be run in an STA and CLSID_WbemLocator
+  // is fine with an STA or MTA. The COM STA task runner accomodates both of
+  // these requirements.
+  base::PostTaskAndReplyWithResult(
+      base::CreateCOMSTATaskRunnerWithTraits(
+          {base::MayBlock(), base::TaskPriority::BACKGROUND,
+           base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN})
+          .get(),
       FROM_HERE,
-      {base::MayBlock(), base::TaskPriority::BACKGROUND,
-       base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN},
-      base::Bind(&AntiVirusMetricsProvider::GetAntiVirusProductsOnFileThread),
-      base::Bind(&AntiVirusMetricsProvider::GotAntiVirusProducts,
-                 weak_ptr_factory_.GetWeakPtr(), done_callback));
+      base::BindOnce(
+          &AntiVirusMetricsProvider::GetAntiVirusProductsOnCOMSTAThread),
+      base::BindOnce(&AntiVirusMetricsProvider::GotAntiVirusProducts,
+                     weak_ptr_factory_.GetWeakPtr(), done_callback));
 }
 
 // static
 std::vector<AntiVirusMetricsProvider::AvProduct>
-AntiVirusMetricsProvider::GetAntiVirusProductsOnFileThread() {
+AntiVirusMetricsProvider::GetAntiVirusProductsOnCOMSTAThread() {
+  base::win::AssertComApartmentType(base::win::ComApartmentType::STA);
+
   std::vector<AvProduct> av_products;
 
   ResultCode result = RESULT_GENERIC_FAILURE;
@@ -232,10 +242,6 @@ AntiVirusMetricsProvider::FillAntiVirusProductsFromWSC(
     std::vector<AvProduct>* products) {
   std::vector<AvProduct> result_list;
   base::AssertBlockingAllowed();
-  base::win::ScopedCOMInitializer com_initializer;
-
-  if (!com_initializer.Succeeded())
-    return RESULT_FAILED_TO_INITIALIZE_COM;
 
   Microsoft::WRL::ComPtr<IWSCProductList> product_list;
   HRESULT result =
@@ -333,10 +339,6 @@ AntiVirusMetricsProvider::FillAntiVirusProductsFromWMI(
     std::vector<AvProduct>* products) {
   std::vector<AvProduct> result_list;
   base::AssertBlockingAllowed();
-  base::win::ScopedCOMInitializer com_initializer;
-
-  if (!com_initializer.Succeeded())
-    return RESULT_FAILED_TO_INITIALIZE_COM;
 
   Microsoft::WRL::ComPtr<IWbemLocator> wmi_locator;
   HRESULT hr =

chrome/browser/metrics/antivirus_metrics_provider_win.h

@@ -77,7 +77,7 @@ class AntiVirusMetricsProvider : public metrics::MetricsProvider {
   static void MaybeAddUnregisteredAntiVirusProducts(
       std::vector<AvProduct>* products);
 
-  static std::vector<AvProduct> GetAntiVirusProductsOnFileThread();
+  static std::vector<AvProduct> GetAntiVirusProductsOnCOMSTAThread();
 
   // Removes anything extraneous from the end of the product name such as
   // versions, years, or anything containing numbers to make it more constant.