[Storage] Blob Storage Refactoring pt 1

storage/browser/blob/blob_data_handle.h

Index: storage/browser/blob/blob_data_handle.h
diff --git a/storage/browser/blob/blob_data_handle.h b/storage/browser/blob/blob_data_handle.h
index 0b1d151c612e078ae6a91c3c052657a4f7d08e6a..47e42984f8df79d4504d1d2449b49a7119589be6 100644
--- a/storage/browser/blob/blob_data_handle.h
+++ b/storage/browser/blob/blob_data_handle.h
@@ -18,52 +18,56 @@ class SequencedTaskRunner;
 
 namespace storage {
 
-class BlobData;
+class BlobDataSnapshot;
 class BlobStorageContext;
 
 // A scoper object for use in chrome's main browser process, ensures
 // the underlying BlobData and its uuid remain in BlobStorageContext's
 // collection for the duration. This object has delete semantics and
-// maybe deleted on any thread.
-class STORAGE_EXPORT BlobDataHandle
+// may be deleted on any thread.
+class STORAGE_EXPORT BlobDataSnapshotHandle
     : public base::SupportsUserData::Data {
  public:
-  BlobDataHandle(const BlobDataHandle& other);  // May be copied on any thread.
-  ~BlobDataHandle() override;  // Maybe be deleted on any thread.
-  BlobData* data() const;  // May only be accessed on the IO thread.
+  BlobDataSnapshotHandle(
+      const BlobDataSnapshotHandle& other);  // May be copied on any thread.
+  ~BlobDataSnapshotHandle() override;        // May be deleted on any thread.
+  const BlobDataSnapshot* data() const;      // May be accessed on any thread.
 
-  std::string uuid() const;  // May be accessed on any thread.
+  const std::string& uuid() const;  // May be accessed on any thread.
 
  private:
-  class BlobDataHandleShared
-      : public base::RefCountedThreadSafe<BlobDataHandleShared> {
+  // Internal class whose destructor is guarenteed to be called on the IO
+  // thread.
+  class BlobDataSnapshotHandleShared
+      : public base::RefCountedThreadSafe<BlobDataSnapshotHandleShared> {
    public:
-    BlobDataHandleShared(BlobData* blob_data,
-                         BlobStorageContext* context,
-                         base::SequencedTaskRunner* task_runner);
+    BlobDataSnapshotHandleShared(BlobDataSnapshot* blob_data,
+                                 BlobStorageContext* context,
+                                 base::SequencedTaskRunner* task_runner);
 
-    BlobData* data() const;
+    BlobDataSnapshot* data() const;
     const std::string& uuid() const;
 
    private:
-    friend class base::DeleteHelper<BlobDataHandleShared>;
-    friend class base::RefCountedThreadSafe<BlobDataHandleShared>;
-    friend class BlobDataHandle;
+    friend class base::DeleteHelper<BlobDataSnapshotHandleShared>;
+    friend class base::RefCountedThreadSafe<BlobDataSnapshotHandleShared>;
+    friend class BlobDataSnapshotHandle;
 
-    virtual ~BlobDataHandleShared();
+    virtual ~BlobDataSnapshotHandleShared();
 
-    scoped_refptr<BlobData> blob_data_;
+    scoped_ptr<BlobDataSnapshot> blob_data_;
     base::WeakPtr<BlobStorageContext> context_;
 
-    DISALLOW_COPY_AND_ASSIGN(BlobDataHandleShared);
+    DISALLOW_COPY_AND_ASSIGN(BlobDataSnapshotHandleShared);
   };
 
   friend class BlobStorageContext;
-  BlobDataHandle(BlobData* blob_data, BlobStorageContext* context,
-                 base::SequencedTaskRunner* task_runner);
+  BlobDataSnapshotHandle(BlobDataSnapshot* blob_data,
+                         BlobStorageContext* context,
+                         base::SequencedTaskRunner* task_runner);
 
   scoped_refptr<base::SequencedTaskRunner> io_task_runner_;
-  scoped_refptr<BlobDataHandleShared> shared_;
+  scoped_refptr<BlobDataSnapshotHandleShared> shared_;
 };
 
 }  // namespace storage