[BlobAsync] Adding better error reporting and some new tests.

storage/browser/blob/blob_storage_context.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef STORAGE_BROWSER_BLOB_BLOB_STORAGE_CONTEXT_H_
 #define STORAGE_BROWSER_BLOB_BLOB_STORAGE_CONTEXT_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 67 matching lines @@
   size_t memory_usage() const { return memory_usage_; }
   size_t blob_count() const { return registry_.blob_count(); }
   size_t memory_available() const {
     return kBlobStorageMaxMemoryUsage - memory_usage_;
   }
 
   const BlobStorageRegistry& registry() { return registry_; }
 
  private:
   using BlobRegistryEntry = BlobStorageRegistry::Entry;
+  using BlobConstructedCallback = BlobStorageRegistry::BlobConstructedCallback;
   friend class content::BlobDispatcherHost;
   friend class BlobAsyncBuilderHost;
   friend class BlobAsyncBuilderHostTest;
   friend class BlobDataHandle;
   friend class BlobDataHandle::BlobDataHandleShared;
   friend class BlobReaderTest;
   FRIEND_TEST_ALL_PREFIXES(BlobReaderTest, HandleBeforeAsyncCancel);
   FRIEND_TEST_ALL_PREFIXES(BlobReaderTest, ReadFromIncompleteBlob);
   friend class BlobStorageContextTest;
   FRIEND_TEST_ALL_PREFIXES(BlobStorageContextTest, IncrementDecrementRef);
@@ skipping 19 matching lines @@
   void IncrementBlobRefCount(const std::string& uuid);
   void DecrementBlobRefCount(const std::string& uuid);
 
   // Methods called by BlobDataHandle:
   // This will return an empty snapshot until the blob is complete.
   // TODO(dmurph): After we make the snapshot method in BlobHandle private, then
   // make this DCHECK on the blob not being complete.
   std::unique_ptr<BlobDataSnapshot> CreateSnapshot(const std::string& uuid);
   bool IsBroken(const std::string& uuid) const;
   bool IsBeingBuilt(const std::string& uuid) const;
-  // Runs |done| when construction completes, with true if it was successful.
+  // Runs |done| when construction completes, with true if it was successful,
+  // and false if there was an error, which is reported in the second argument
+  // of the callback.
   void RunOnConstructionComplete(const std::string& uuid,
-                                 const base::Callback<void(bool)>& done);
+                                 const BlobConstructedCallback& done);
 
   // Appends the given blob item to the blob builder.  The new blob
   // retains ownership of data_item if applicable, and returns false if there
   // was an error and pouplates the error_code.  We can either have an error of:
   // OUT_OF_MEMORY: We are out of memory to store this blob.
   // REFERENCED_BLOB_BROKEN: One of the referenced blobs is broken.
   bool AppendAllocatedBlobItem(const std::string& target_blob_uuid,
                                scoped_refptr<BlobDataItem> data_item,
                                InternalBlobData::Builder* target_blob_data,
                                IPCBlobCreationCancelCode* error_code);
@@ skipping 19 matching lines @@
   // we count only the items of TYPE_DATA which are held in memory and not
   // items of TYPE_FILE.
   size_t memory_usage_;
 
   DISALLOW_COPY_AND_ASSIGN(BlobStorageContext);
 };
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_BLOB_BLOB_STORAGE_CONTEXT_H_