support setting quota of dom storage

Author: rogerwang

content/common/dom_storage/dom_storage_map.cc

@@ -27,10 +27,14 @@ size_t CountBytes(const DOMStorageValuesMap& values) {
 
 }  // namespace
 
+size_t DomStorageMap::quota_override_ = 0;
+
 DOMStorageMap::DOMStorageMap(size_t quota)
     : bytes_used_(0),
       quota_(quota) {
   ResetKeyIterator();
+  if (quota_override_)
+    quota_ = quota_override_;
 }
 
 DOMStorageMap::~DOMStorageMap() {}
@@ -77,8 +81,8 @@ bool DOMStorageMap::SetItem(
 
   // Only check quota if the size is increasing, this allows
   // shrinking changes to pre-existing files that are over budget.
-  // if (new_item_size > old_item_size && new_bytes_used > quota_)
-  //  return false;
+  if (new_item_size > old_item_size && new_bytes_used > quota_)
+    return false;
 
   values_[key] = base::NullableString16(value, false);
   ResetKeyIterator();

content/common/dom_storage/dom_storage_map.h

@@ -21,7 +21,8 @@ namespace content {
 class CONTENT_EXPORT DOMStorageMap
     : public base::RefCountedThreadSafe<DOMStorageMap> {
  public:
-  explicit DOMStorageMap(size_t quota);
+  explicit DomStorageMap(size_t quota);
+  static void SetQuotaOverride(size_t quota) {quota_override_ = quota; }
 
   unsigned Length() const;
   base::NullableString16 Key(unsigned index);
@@ -44,7 +45,7 @@ class CONTENT_EXPORT DOMStorageMap
 
   size_t bytes_used() const { return bytes_used_; }
   size_t quota() const { return quota_; }
-  void set_quota(size_t quota) { quota_ = quota; }
+  void set_quota(size_t quota) { quota_ = quota > quota_override_ ? quota : quota_override_; }
 
  private:
   friend class base::RefCountedThreadSafe<DOMStorageMap>;
@@ -57,6 +58,7 @@ class CONTENT_EXPORT DOMStorageMap
   unsigned last_key_index_;
   size_t bytes_used_;
   size_t quota_;
+  static size_t quota_override_;
 };
 
 }  // namespace content