Bug 1462666 - increase default autocompact threshold "mail.purge_threshhold" from 20MB to 200MB. r=mkmelin

mail/components/preferences/advanced.inc.xul

@@ -265,7 +265,7 @@
                           preference="mail.prompt_purge_threshhold"
                           oncommand="gAdvancedPane.updateCompactOptions(this.checked);"/>
                 <html:input id="offlineCompactFolderMin" type="number" class="size4"
-                            min="1" max="2048" value="20"
+                            min="1" max="2048" value="200"
                             preference="mail.purge_threshhold_mb"
                             aria-labelledby="offlineCompactFolder offlineCompactFolderMin compactFolderMB"/>
                 <label id="compactFolderMB" value="&offlineCompactFoldersMB.label;"/>

mailnews/base/util/nsMsgDBFolder.cpp

@@ -1875,7 +1875,7 @@ nsresult nsMsgDBFolder::GetPurgeThreshold(int32_t *aThreshold) {
   nsCOMPtr<nsIPrefBranch> prefBranch =
       do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
   if (NS_SUCCEEDED(rv) && prefBranch) {
-    int32_t thresholdMB = 20;
+    int32_t thresholdMB = 200;
     bool thresholdMigrated = false;
     prefBranch->GetIntPref(PREF_MAIL_PURGE_THRESHOLD_MB, &thresholdMB);
     prefBranch->GetBoolPref(PREF_MAIL_PURGE_MIGRATED, &thresholdMigrated);

mailnews/mailnews.js

@@ -278,7 +278,7 @@ pref("mail.warn_on_collapsed_thread_operation", true);
 pref("mail.warn_on_shift_delete", true);
 pref("news.warn_on_delete", true);
 pref("mail.warn_on_delete_from_trash", true);
-pref("mail.purge_threshhold_mb", 20);
+pref("mail.purge_threshhold_mb", 200);
 pref("mail.prompt_purge_threshhold",       true);
 pref("mail.purge.ask",                     true);