Closing a guest session clears all browsing history.

chrome/browser/ui/browser.cc

Index: chrome/browser/ui/browser.cc
diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
index f438efd2273adeda29b552ea373597101c6020ed..95ef5133f65564225691356f783cdc3669c32b16 100644
--- a/chrome/browser/ui/browser.cc
+++ b/chrome/browser/ui/browser.cc
@@ -34,6 +34,8 @@
 #include "chrome/browser/background/background_contents_service_factory.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_shutdown.h"
+#include "chrome/browser/browsing_data/browsing_data_helper.h"
+#include "chrome/browser/browsing_data/browsing_data_remover.h"
 #include "chrome/browser/character_encoding.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/content_settings/tab_specific_content_settings.h"
@@ -511,9 +513,22 @@ Browser::~Browser() {
 
   if (profile_->IsOffTheRecord() &&
       !BrowserList::IsOffTheRecordSessionActiveForProfile(profile_)) {
-    // An incognito profile is no longer needed, this indirectly frees
-    // its cache and cookies once it gets destroyed at the appropriate time.
-    ProfileDestroyer::DestroyProfileWhenAppropriate(profile_);
+    if (profile_->IsGuestSession()) {
+      // Clear all browsing data once a Guest Session completes. The Guest
+      // profile has BrowserContextKeyedServices that the Incognito profile
+      // doesn't, so the ProfileDestroyer can't delete it properly.
+      // TODO(mlerman): Delete the guest using an improved ProfileDestroyer.
+      BrowsingDataRemover* data_remover =
+          BrowsingDataRemover::CreateForUnboundedRange(profile_);
+      data_remover->Remove(BrowsingDataRemover::REMOVE_ALL ^
+                               BrowsingDataRemover::REMOVE_DOWNLOADS,

[battre, 2015/02/11 15:19:25]

Looking at
https://developer.chrome.com/extensions/browsingData#method-removeDownloads (I
did not check the code), REMOVE_DOWNLOADS seems to clear the list of downloaded
files but not to delete the files. Maybe REMOVE_ALL is sufficient here.

[Bernhard Bauer, 2015/02/11 16:04:28]

Yup, we never delete downloaded files.

[Mike Lerman, 2015/02/12 15:36:23]

Okay. Done.

+                           BrowsingDataHelper::ALL);
+      // BrowsingDataRemover deletes itself.
+    } else {
+      // An incognito profile is no longer needed, this indirectly frees
+      // its cache and cookies once it gets destroyed at the appropriate time.
+      ProfileDestroyer::DestroyProfileWhenAppropriate(profile_);
+    }
   }
 
   // There may be pending file dialogs, we need to tell them that we've gone