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

storage/browser/blob/blob_reader.cc

Index: storage/browser/blob/blob_reader.cc
diff --git a/storage/browser/blob/blob_reader.cc b/storage/browser/blob/blob_reader.cc
index 0ac6622b958da020bcf3ec8dc1ddf3cd7f259909..2a07a83960c6dc1679ed679d850fc9f78b7e45d4 100644
--- a/storage/browser/blob/blob_reader.cc
+++ b/storage/browser/blob/blob_reader.cc
@@ -37,6 +37,24 @@ bool IsFileType(DataElement::Type type) {
       return false;
   }
 }
+
+int TransformBlobErrorToNetError(IPCBlobCreationCancelCode reason) {
+  switch (reason) {
+    case IPCBlobCreationCancelCode::UNKNOWN:
+      return net::ERR_FAILED;
+    case IPCBlobCreationCancelCode::OUT_OF_MEMORY:
+      return net::ERR_OUT_OF_MEMORY;
+    case IPCBlobCreationCancelCode::FILE_WRITE_FAILED:
+      return net::ERR_FILE_NO_SPACE;
+    case IPCBlobCreationCancelCode::SOURCE_DIED_IN_TRANSIT:
+      return net::ERR_UNEXPECTED;
+    case IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING:
+      return net::ERR_UNEXPECTED;
+    case IPCBlobCreationCancelCode::REFERENCED_BLOB_BROKEN:
+      return net::ERR_INVALID_HANDLE;
+  }
+  NOTREACHED();
+}
 }  // namespace
 
 BlobReader::FileStreamReaderProvider::~FileStreamReaderProvider() {}
@@ -183,9 +201,10 @@ BlobReader::Status BlobReader::ReportError(int net_error) {
 }
 
 void BlobReader::AsyncCalculateSize(const net::CompletionCallback& done,
-                                    bool async_succeeded) {
+                                    bool async_succeeded,
+                                    IPCBlobCreationCancelCode reason) {
   if (!async_succeeded) {
-    InvalidateCallbacksAndDone(net::ERR_FAILED, done);
+    InvalidateCallbacksAndDone(TransformBlobErrorToNetError(reason), done);
     return;
   }
   DCHECK(!blob_handle_->IsBroken()) << "Callback should have returned false.";