[Win] Add reporting of total number of modules loaded in browser process.

chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc

Index: chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
diff --git a/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc b/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
index 4c343f28538f32e08faf7f66bf642ef99bab2c7c..9602e4a3abefbcb2ba2adeca1e1436f30152e5ee 100644
--- a/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
+++ b/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
@@ -19,6 +19,7 @@
 #include "chrome/browser/about_flags.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_browser_main.h"
+#include "chrome/browser/enumerate_modules_model_win.h"
 #include "chrome/browser/mac/bluetooth_utility.h"
 #include "chrome/browser/shell_integration.h"
 #include "components/flags_ui/pref_service_flags_storage.h"
@@ -136,6 +137,54 @@ void RecordMicroArchitectureStats() {
                               base::SysInfo::NumberOfProcessors());
 }
 
+#if defined(OS_WIN)
+// Gathers third party module information.
+void GatherThirdPartyModuleMetricsOnBlockingPool() {
+  // Get the module list. If it's not yet ready post a delayed task to try again
+  // in a bit.
+  auto modules = EnumerateModulesModel::GetInstance();
+  std::unique_ptr<base::ListValue> list(modules->GetModuleList());
+  if (list.get() == nullptr) {
+    content::BrowserThread::GetBlockingPool()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&GatherThirdPartyModuleMetricsOnBlockingPool),
+        base::TimeDelta::FromSeconds(1));

[grt (UTC plus 2), 2016/06/06 01:38:57]

please do something better than polling for the result. i see that
EnumerateModulesModel uses NotificationService, which is on the chopping block
(https://crbug.com/268984). perhaps now is the time to replace
NOTIFICATION_MODULE_LIST_ENUMERATED with a better observer/delegate pattern.

+    return;
+  }
+
+  // Process the module list.
+  size_t microsoft_modules = 0;
+  for (size_t i = 0; i < list->GetSize(); ++i) {
+    base::DictionaryValue* module = nullptr;
+    CHECK(list->GetDictionary(i, &module));

[rkaplow, 2016/06/03 18:17:31]

DCHECK here and below

[rkaplow, 2016/06/03 18:24:31]

that is, should DCHECK on the result (since it still needs to execute)

+
+    base::string16 signer;
+    CHECK(module->GetString("digital_signer", &signer));
+    if (signer.find(L"Microsoft") != signer.npos)
+      ++microsoft_modules;
+  }
+
+  // Report the total number of modules present.
+  UMA_HISTOGRAM_CUSTOM_COUNTS("ThirdPartyModules.Modules.Microsoft",
+                              microsoft_modules, 1, 500, 50);
+  UMA_HISTOGRAM_CUSTOM_COUNTS("ThirdPartyModules.Modules.Total",
+                              list->GetSize(), 1, 500, 50);
+}
+
+// Initiates recording of third party modules. The actual module enumeration
+// ends up being performed on the file thread, while the results are eventually
+// retrieved and processed on the blocking pool.
+void InitiateThirdPartyModuleMetricsOnUIThread() {
+  // The module scanning wants to be kicked off from the UI thread.
+  auto modules = EnumerateModulesModel::GetInstance();
+  modules->ScanNow();
+  content::BrowserThread::GetBlockingPool()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&GatherThirdPartyModuleMetricsOnBlockingPool),
+      base::TimeDelta::FromSeconds(1));
+}
+#endif  // defined(OS_WIN)
+
 // Called on the blocking pool some time after startup to avoid slowing down
 // startup with metrics that aren't trivial to compute.
 void RecordStartupMetricsOnBlockingPool() {
@@ -355,6 +404,16 @@ void ChromeBrowserMainExtraPartsMetrics::PostBrowserStart() {
       base::Bind(&RecordStartupMetricsOnBlockingPool),
       base::TimeDelta::FromSeconds(kStartupMetricsGatheringDelaySeconds));
 
+#if defined(OS_WIN)
+  // Initiate third party module gathering on the UI thread. The actual
+  // reporting will end up happening in the blocking pool.
+  content::BrowserThread::PostDelayedTask(
+      content::BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&InitiateThirdPartyModuleMetricsOnUIThread),
+      base::TimeDelta::FromSeconds(kStartupMetricsGatheringDelaySeconds));
+#endif  // defined(OS_WIN)
+
   display_count_ = display::Screen::GetScreen()->GetNumDisplays();
   UMA_HISTOGRAM_COUNTS_100("Hardware.Display.Count.OnStartup", display_count_);
   display::Screen::GetScreen()->AddObserver(this);