[win] Enable ModuleDatabase behind a flag.

chrome/browser/chrome_browser_field_trials_desktop.cc

Index: chrome/browser/chrome_browser_field_trials_desktop.cc
diff --git a/chrome/browser/chrome_browser_field_trials_desktop.cc b/chrome/browser/chrome_browser_field_trials_desktop.cc
index 3634168cb7e1cd3d842b0b3815c087b7e1a34004..b57e7fbe4a83a72bfb3ea630984932a3ce340472 100644
--- a/chrome/browser/chrome_browser_field_trials_desktop.cc
+++ b/chrome/browser/chrome_browser_field_trials_desktop.cc
@@ -20,6 +20,7 @@
 #include "base/path_service.h"
 #include "chrome/browser/features.h"
 #include "chrome/browser/prerender/prerender_field_trial.h"
+#include "chrome/common/chrome_features.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "components/browser_watcher/features.h"
@@ -147,6 +148,7 @@ void SetupDesktopFieldTrials() {
   SetupStunProbeTrial();
 #if defined(OS_WIN)
   SetupStabilityDebugging();
+  base::FeatureList::IsEnabled(features::kModuleDatabase);

[grt (UTC plus 2), 2017/01/06 09:44:57]

apologies if this is a silly question, but why isn't the call in
ChromeBrowserMainPartsWin::PostProfileInit sufficient? i've never needed to do
anything like this here before. have i been doing it wrong?

[chrisha, 2017/01/10 21:01:45]

AFAIK it's not a big deal, it's just that the earlier you "initialize" them the
higher the likelihood of them showing up in the system profile with crash
reports. I was just copying the code below with kDesktopFastShutdown. I'm not
sure if this is good practice or not...

 #endif  // defined(OS_WIN)
   // Activate the experiment as early as possible to increase its visibility
   // (e.g. the likelihood of its presence in the serialized system profile).