storage: clean up cache storage initialization

Instead of going ui -> io thread -> cache storage task runner,
instead have the ui just post two tasks.
This should cut down on any potential races on startup.

This is a followup to comments left on:
https://chromium-review.googlesource.com/c/chromium/src/+/1907095/4#message-d81d6b0b2d2ab774ba9aeff7674e1c4b842fe342

Bug: 1022104
Change-Id: Icdfd30c36969795ba3625179137360258171b170
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1931580
Commit-Queue: enne <enne@chromium.org>
Reviewed-by: Ben Kelly <wanderview@chromium.org>
Reviewed-by: Marijn Kruisselbrink <mek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#718823}

content/browser/cache_storage/cache_storage_context_impl.cc

@@ -128,15 +128,25 @@ void CacheStorageContextImpl::SetBlobParametersForCache(
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   if (!blob_storage_context)
     return;
-  // We can only get a mojo interface for BlobStorageContext on the IO thread.
-  // Bounce there first before setting the context on the manager.
+
+  // TODO(enne): this remote will need to be sent to the storage service when
+  // cache storage is moved.
+  mojo::PendingRemote<storage::mojom::BlobStorageContext> remote;
+  auto receiver = remote.InitWithNewPipeAndPassReceiver();
+  task_runner_->PostTask(
+      FROM_HERE,
+      base::BindOnce(
+          &CacheStorageContextImpl::SetBlobParametersForCacheOnTaskRunner, this,
+          std::move(remote)));
+
+  // We can only bind a mojo interface for BlobStorageContext on the IO thread.
   // TODO(enne): clean this up in the future to not require this bounce and
   // to have this mojo context live on the cache storage sequence.
   base::PostTask(
       FROM_HERE, {BrowserThread::IO},
       base::BindOnce(
-          &CacheStorageContextImpl::GetBlobStorageMojoContextOnIOThread, this,
-          base::RetainedRef(blob_storage_context)));
+          &CacheStorageContextImpl::BindBlobStorageMojoContextOnIOThread, this,
+          base::RetainedRef(blob_storage_context), std::move(receiver)));
 }
 
 void CacheStorageContextImpl::GetAllOriginsInfo(
@@ -250,22 +260,14 @@ void CacheStorageContextImpl::ShutdownOnTaskRunner() {
   cache_manager_ = nullptr;
 }
 
-void CacheStorageContextImpl::GetBlobStorageMojoContextOnIOThread(
-    ChromeBlobStorageContext* blob_storage_context) {
+void CacheStorageContextImpl::BindBlobStorageMojoContextOnIOThread(
+    ChromeBlobStorageContext* blob_storage_context,
+    mojo::PendingReceiver<storage::mojom::BlobStorageContext> receiver) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(blob_storage_context);
+  DCHECK(receiver.is_valid());
 
-  mojo::PendingRemote<storage::mojom::BlobStorageContext> remote;
-  blob_storage_context->BindMojoContext(
-      remote.InitWithNewPipeAndPassReceiver());
-
-  // TODO(enne): this remote will need to be sent to the storage service when
-  // cache storage is moved.
-  task_runner_->PostTask(
-      FROM_HERE,
-      base::BindOnce(
-          &CacheStorageContextImpl::SetBlobParametersForCacheOnTaskRunner, this,
-          std::move(remote)));
+  blob_storage_context->BindMojoContext(std::move(receiver));
 }
 
 void CacheStorageContextImpl::SetBlobParametersForCacheOnTaskRunner(

content/browser/cache_storage/cache_storage_context_impl.h

@@ -121,8 +121,9 @@ class CONTENT_EXPORT CacheStorageContextImpl
 
   void ShutdownOnTaskRunner();
 
-  void GetBlobStorageMojoContextOnIOThread(
-      ChromeBlobStorageContext* blob_storage_context);
+  void BindBlobStorageMojoContextOnIOThread(
+      ChromeBlobStorageContext* blob_storage_context,
+      mojo::PendingReceiver<storage::mojom::BlobStorageContext> receiver);
 
   void SetBlobParametersForCacheOnTaskRunner(
       mojo::PendingRemote<storage::mojom::BlobStorageContext> remote);