Added a feature flag for ChromePromptImpl::DisableExtensions

Details:
Flag name: kChromeCleanupExtensionsFeature
When ON, extensions are included when prompting the user for UwS cleanup.
When OFF, extensions are NOT included when prompting the user for UwS cleanup.

Bug: 904958
Change-Id: Ie483ddb64de11de015429557343f0ee5c4676ff5
Reviewed-on: https://chromium-review.googlesource.com/c/1337790
Commit-Queue: Sebastien Lalancette <seblalancette@chromium.org>
Reviewed-by: Joe Mason <joenotcharles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609859}

chrome/browser/safe_browsing/chrome_cleaner/srt_chrome_prompt_impl.cc

@@ -14,6 +14,7 @@
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/safe_browsing/chrome_cleaner/srt_field_trial_win.h"
 #include "components/crx_file/id_util.h"
 #include "content/public/browser/browser_thread.h"
 #include "extensions/browser/uninstall_reason.h"
@@ -53,35 +54,41 @@ void ChromePromptImpl::PromptUser(
   using ExtensionCollection = ChromeCleanerScannerResults::ExtensionCollection;
 
   if (on_prompt_user_) {
+    if (base::FeatureList::IsEnabled(kChromeCleanupExtensionsFeature) &&
+        extension_ids) {
+      extension_ids_ = extension_ids.value();
+    } else {
+      extension_ids_.clear();
+    }
+
     ChromeCleanerScannerResults scanner_results(
         FileCollection(files_to_delete.begin(), files_to_delete.end()),
         registry_keys ? RegistryKeyCollection(registry_keys->begin(),
                                               registry_keys->end())
                       : RegistryKeyCollection(),
-        extension_ids
-            ? ExtensionCollection(extension_ids->begin(), extension_ids->end())
-            : ExtensionCollection());
-    if (extension_ids.has_value()) {
-      extension_ids_ = extension_ids;
-    }
+        extension_ids_.empty() ? ExtensionCollection()
+                               : ExtensionCollection(extension_ids_.begin(),
+                                                     extension_ids_.end()));
+
     std::move(on_prompt_user_)
         .Run(std::move(scanner_results), std::move(callback));
   }
 }
 
+// The |extensions_ids| passed to this function are a subset of the
+// |extension_ids| passed to PromptUser because the extensions are not all
+// disabled at the same time.
 void ChromePromptImpl::DisableExtensions(
     const std::vector<base::string16>& extension_ids,
     ChromePrompt::DisableExtensionsCallback callback) {
-  if (extension_service_ == nullptr || !extension_ids_.has_value()) {
+  if (extension_service_ == nullptr || extension_ids_.empty()) {
     std::move(callback).Run(false);
     return;
   }
   // Clear the stored extension_ids by moving it onto this stack frame,
   // so subsequent calls will fail.
-  base::Optional<std::vector<base::string16>> optional_verified_extension_ids{};
-  extension_ids_.swap(optional_verified_extension_ids);
-  std::vector<base::string16> verified_extension_ids =
-      optional_verified_extension_ids.value();
+  std::vector<base::string16> verified_extension_ids{};
+  extension_ids_.swap(verified_extension_ids);
   bool ids_are_valid = std::all_of(
       extension_ids.begin(), extension_ids.end(),
       [this, &verified_extension_ids](const base::string16& id) {

chrome/browser/safe_browsing/chrome_cleaner/srt_chrome_prompt_impl.h

@@ -50,7 +50,7 @@ class ChromePromptImpl : public chrome_cleaner::mojom::ChromePrompt {
   mojo::Binding<chrome_cleaner::mojom::ChromePrompt> binding_;
   extensions::ExtensionService* extension_service_;
   OnPromptUser on_prompt_user_;
-  base::Optional<std::vector<base::string16>> extension_ids_;
+  std::vector<base::string16> extension_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromePromptImpl);
 };

chrome/browser/safe_browsing/chrome_cleaner/srt_field_trial_win.cc

@@ -47,6 +47,9 @@ const base::Feature kChromeCleanupDistributionFeature{
 const base::Feature kChromeCleanupQuarantineFeature{
     "ChromeCleanupQuarantine", base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kChromeCleanupExtensionsFeature{
+    "ChromeCleanupExtensions", base::FEATURE_DISABLED_BY_DEFAULT};
+
 bool IsInSRTPromptFieldTrialGroups() {
   return !base::StartsWith(base::FieldTrialList::FindFullName(kSRTPromptTrial),
                            kSRTPromptOffGroup, base::CompareCase::SENSITIVE);

chrome/browser/safe_browsing/chrome_cleaner/srt_field_trial_win.h

@@ -74,6 +74,10 @@ extern const base::Feature kChromeCleanupDistributionFeature;
 // files.
 extern const base::Feature kChromeCleanupQuarantineFeature;
 
+// Extensions cleanup feature. When enabled, Chrome Cleaner will prompt users
+// for, and cleanup, bad extensions.
+extern const base::Feature kChromeCleanupExtensionsFeature;
+
 extern const char kSRTPromptTrial[];
 
 // Returns true if this Chrome is in a field trial group which shows the SRT