Improve IndexedDB's quota support

content/browser/in_process_webkit/indexed_db_quota_client.cc

Index: content/browser/in_process_webkit/indexed_db_quota_client.cc
diff --git a/content/browser/in_process_webkit/indexed_db_quota_client.cc b/content/browser/in_process_webkit/indexed_db_quota_client.cc
index 4c3aaac2312071e613e8a82fe403add1dd012af4..1af8c75632d7fa2a6d3ddf1a236dc615fa556650 100644
--- a/content/browser/in_process_webkit/indexed_db_quota_client.cc
+++ b/content/browser/in_process_webkit/indexed_db_quota_client.cc
@@ -31,6 +31,30 @@ class IndexedDBQuotaClient::HelperTask : public quota::QuotaThreadTask {
   scoped_refptr<IndexedDBContext> indexed_db_context_;
 };
 
+class IndexedDBQuotaClient::DeleteOriginTask : public HelperTask {
+ public:
+  DeleteOriginTask(IndexedDBQuotaClient* client,
+                   base::MessageLoopProxy* webkit_thread_message_loop,
+                   const GURL& origin_url,
+                   DeletionCallback* callback)
+      : HelperTask(client, webkit_thread_message_loop),
+        origin_url_(origin_url), callback_(callback) {
+  }
+ private:
+  virtual void RunOnTargetThread() OVERRIDE {
+    indexed_db_context_->DeleteIndexedDBForOrigin(origin_url_);
+  }
+  virtual void Aborted() OVERRIDE {
+    callback_.reset();
+  }
+  virtual void Completed() OVERRIDE {
+    callback_->Run(quota::kQuotaStatusOk);
+    callback_.reset();
+  }
+  GURL origin_url_;
+  scoped_ptr<DeletionCallback> callback_;
+};
+
 class IndexedDBQuotaClient::GetOriginUsageTask : public HelperTask {
  public:
   GetOriginUsageTask(
@@ -43,12 +67,10 @@ class IndexedDBQuotaClient::GetOriginUsageTask : public HelperTask {
 
  private:
   virtual void RunOnTargetThread() OVERRIDE {
-    string16 origin_id = DatabaseUtil::GetOriginIdentifier(origin_url_);
-    FilePath file_path = indexed_db_context_->GetIndexedDBFilePath(origin_id);
-    usage_ = 0;
-    usage_ = file_util::ComputeDirectorySize(file_path);
+    usage_ = indexed_db_context_->InitializeDiskUsage(origin_url_);

[michaeln, 2011/08/04 22:11:55]

Its a little odd to see this function calling an 'initialize' method. Feels like
GetOriginDiskUsage() would be better.

Currently, sometime around the first storage access system wide, the QM will
query each client for each origin that is using storage of some form via the
GetOriginUsage stuff. Origins that are not yet using storage will not be queried
until sometime shortly after it's first access, like opening an indexedDB. The
trigger for this query is a call to QM->GetUsageAndQuota(origin).

I don't think you can depend on these queries arriving in advance of indexedDB
operations. Consider if the first call to QM->GetUsageAndQuota for a particular
origin originates from the indexedDB system.

[dgrogan, 2011/08/04 23:44:56]

You're right.  Changed.
This patch adds a EnsureDiskUsageCacheInitialized method that hopefully handles
this.

   }
   virtual void Completed() OVERRIDE {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
     client_->DidGetOriginUsage(origin_url_, usage_);
   }
   GURL origin_url_;
@@ -202,9 +224,16 @@ void IndexedDBQuotaClient::GetOriginsForHost(
 void IndexedDBQuotaClient::DeleteOriginData(const GURL& origin,
                                            quota::StorageType type,
                                            DeletionCallback* callback) {
-  // TODO(tzik): implement me
-  callback->Run(quota::kQuotaErrorNotSupported);
-  delete callback;
+  if (type != quota::kStorageTypeTemporary) {
+    callback->Run(quota::kQuotaErrorNotSupported);
+    return;
+  }
+  scoped_refptr<DeleteOriginTask> task(
+      new DeleteOriginTask(this,
+                           webkit_thread_message_loop_,
+                           origin,
+                           callback));
+  task->Start();
 }
 
 void IndexedDBQuotaClient::DidGetOriginUsage(