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

chrome/browser/ui/webui/conflicts_ui.cc

Index: chrome/browser/ui/webui/conflicts_ui.cc
diff --git a/chrome/browser/ui/webui/conflicts_ui.cc b/chrome/browser/ui/webui/conflicts_ui.cc
index d1e0e1d06fe87529c11e8634fa453835ede4bed4..b08e94b67df65b64ad99bf4bbbc2c95ec4428e3c 100644
--- a/chrome/browser/ui/webui/conflicts_ui.cc
+++ b/chrome/browser/ui/webui/conflicts_ui.cc
@@ -16,15 +16,11 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "build/build_config.h"
-#include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/win/enumerate_modules_model.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/chromium_strings.h"
 #include "chrome/grit/generated_resources.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "content/public/browser/notification_service.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_ui.h"
@@ -77,9 +73,9 @@ content::WebUIDataSource* CreateConflictsUIHTMLSource() {
 //
 ////////////////////////////////////////////////////////////////////////////////
 
-// The handler for JavaScript messages for the about:flags page.
+// The handler for JavaScript messages for the about:conflicts page.
 class ConflictsDOMHandler : public WebUIMessageHandler,
-                            public content::NotificationObserver {
+                            public EnumerateModulesModel::Observer {
  public:
   ConflictsDOMHandler() {}
   ~ConflictsDOMHandler() override {}
@@ -93,11 +89,8 @@ class ConflictsDOMHandler : public WebUIMessageHandler,
  private:
   void SendModuleList();
 
-  void Observe(int type,
-               const content::NotificationSource& source,
-               const content::NotificationDetails& details) override;
-
-  content::NotificationRegistrar registrar_;
+  // EnumerateModulesModel::Observer implementation.
+  void OnScanCompleted() override;
 
   DISALLOW_COPY_AND_ASSIGN(ConflictsDOMHandler);
 };
@@ -109,10 +102,11 @@ void ConflictsDOMHandler::RegisterMessages() {
 }
 
 void ConflictsDOMHandler::HandleRequestModuleList(const base::ListValue* args) {
-  // This request is handled asynchronously. See Observe for when we reply back.
-  registrar_.Add(this, chrome::NOTIFICATION_MODULE_LIST_ENUMERATED,
-                 content::NotificationService::AllSources());
-  EnumerateModulesModel::GetInstance()->ScanNow();
+  // The request is handled asynchronously, and will callback via
+  // OnScanCompleted on completion.
+  auto model = EnumerateModulesModel::GetInstance();

[Lei Zhang, 2016/08/04 14:33:32]

auto*

[chrisha, 2016/08/12 19:04:40]

Done.

+  model->AddObserver(this);

[Lei Zhang, 2016/08/04 14:33:32]

Can this end up adding the same observer twice? This is a JS handler right? Can
JS send 2 requestModuleList messages before OnScanCompleted() ?

[Peter Kasting, 2016/08/05 00:10:08]

If this is a real concern, using a ScopedObserver would allow this to be checked
simply using the IsObserving() method.  OTOH, that's a less-helpful pattern
otherwise in this class, since the RemoveObserver call does not happen at
destruction.  (Although, do you need to worry about being destroyed without
OnScanCompleted() being reached?  Because if so then you do need such a call.)

[chrisha, 2016/08/12 19:04:40]

The ScopedObserver is cleaner IMO, and also allows me to handle this possible
case of 'abuse' from the JS. Switched to using that.

[chrisha, 2016/08/12 19:04:40]

Shouldn't be possible from how the JS code is written, but using a
ScopedObserver to safely handle this case is easy enough.

+  model->ScanNow();
 }
 
 void ConflictsDOMHandler::SendModuleList() {
@@ -141,13 +135,9 @@ void ConflictsDOMHandler::SendModuleList() {
   web_ui()->CallJavascriptFunctionUnsafe("returnModuleList", results);
 }
 
-void ConflictsDOMHandler::Observe(int type,
-                                  const content::NotificationSource& source,
-                                  const content::NotificationDetails& details) {
-  DCHECK_EQ(chrome::NOTIFICATION_MODULE_LIST_ENUMERATED, type);
-
+void ConflictsDOMHandler::OnScanCompleted() {
   SendModuleList();
-  registrar_.RemoveAll();
+  EnumerateModulesModel::GetInstance()->RemoveObserver(this);
 }
 
 }  // namespace