[BlobAsync] Faster shortcuttin, make renderer controller leaky & alive.

storage/browser/blob/blob_async_builder_host.cc

 // Copyright 2015 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.
 
 #include "storage/browser/blob/blob_async_builder_host.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
@@ skipping 78 matching lines @@
   return BlobTransportResult::DONE;
 }
 
 BlobTransportResult BlobAsyncBuilderHost::StartBuildingBlob(
     const std::string& uuid,
     const std::vector<DataElement>& elements,
     size_t memory_available,
     BlobStorageContext* context,
     const RequestMemoryCallback& request_memory) {
   DCHECK(context);
-  if (async_blob_map_.find(uuid) == async_blob_map_.end()) {
-    return BlobTransportResult::BAD_IPC;
-  }
 
   // Step 1: Get the sizes.
   size_t shortcut_memory_size_bytes = 0;
   uint64_t total_memory_size_bytes = 0;
   if (!CalculateBlobMemorySize(elements, &shortcut_memory_size_bytes,
                                &total_memory_size_bytes)) {
     CancelBuildingBlob(uuid, IPCBlobCreationCancelCode::UNKNOWN, context);
     return BlobTransportResult::BAD_IPC;
   }
 
@@ skipping 152 matching lines @@
     state->num_fulfilled_requests++;
   }
   return ContinueBlobMemoryRequests(uuid, context);
 }
 
 void BlobAsyncBuilderHost::CancelBuildingBlob(const std::string& uuid,
                                               IPCBlobCreationCancelCode code,
                                               BlobStorageContext* context) {
   DCHECK(context);
   auto state_it = async_blob_map_.find(uuid);
-  if (state_it == async_blob_map_.end()) {
-    return;
-  }
+  DCHECK(state_it != async_blob_map_.end());
   // We can have the blob dereferenced by the renderer, but have it still being
   // 'built'. In this case, it's destructed in the context, but we still have
   // it in our map. Hence we make sure the context has the entry before
   // calling cancel.
   if (context->registry().HasEntry(uuid))
     context->CancelPendingBlob(uuid, code);
   async_blob_map_.erase(state_it);
 }
 
 void BlobAsyncBuilderHost::CancelAll(BlobStorageContext* context) {
@@ skipping 144 matching lines @@
     if (state->num_referenced_blobs_building > 0) {
       // We wait until referenced blobs are done.
       return;
     }
   }
   context->CompletePendingBlob(state->data_builder);
   async_blob_map_.erase(state->data_builder.uuid());
 }
 
 }  // namespace storage