[DOMStorage] Do not try purging caches when no database is open

content/browser/dom_storage/dom_storage_context_impl.cc

Index: content/browser/dom_storage/dom_storage_context_impl.cc
diff --git a/content/browser/dom_storage/dom_storage_context_impl.cc b/content/browser/dom_storage/dom_storage_context_impl.cc
index 3ef365c2bb045af1bd4c4f3931d2fc9d5f7a5da9..325bbab2c18ae62dfad39ac086ab7aa1b79e72de 100644
--- a/content/browser/dom_storage/dom_storage_context_impl.cc
+++ b/content/browser/dom_storage/dom_storage_context_impl.cc
@@ -445,9 +445,6 @@ void DOMStorageContextImpl::PurgeMemory(PurgeOption purge_option) {
     // Purging is done based on the cache sizes without including the database
     // size since it can be expensive trying to estimate the sqlite usage for
     // all databases. For low end devices purge all inactive areas.
-    if (!initial_stats.inactive_area_count)
-      return;
-
     if (initial_stats.total_cache_size > kMaxCacheSize)
       purge_reason = "SizeLimitExceeded";
     else if (initial_stats.total_area_count > kMaxStorageAreaCount)
@@ -460,13 +457,18 @@ void DOMStorageContextImpl::PurgeMemory(PurgeOption purge_option) {
     purge_option = PURGE_UNOPENED;
   }
 
+  // Return if no areas can be purged with the given option.
   bool aggressively = purge_option == PURGE_AGGRESSIVE;
+  if ((aggressively && !initial_stats.total_area_count) ||
+      (!aggressively && !initial_stats.inactive_area_count)) {
+    return;
+  }
   for (const auto& it : namespaces_)
     it.second->PurgeMemory(aggressively);
 
   // Track the size of cache purged.
   if (!purge_reason) {

[michaeln, 2016/06/27 21:51:15]

nit: it might be nice to set purge_reason in all cases up above where your
figuring out the options, before calling ->PurgeMemory

[ssid, 2016/06/27 22:00:37]

Done.

-    if (purge_option == PURGE_AGGRESSIVE)
+    if (aggressively)
       purge_reason = "AggressivePurgeTriggered";
     else
       purge_reason = "ModeratePurgeTriggered";