Blobs: Add sequence checkers to storage::MojoBlobReader.

Change-Id: Iae148260df76be6b37e22ea4a95bdbd81e0e35b7
Reviewed-on: https://chromium-review.googlesource.com/1176971
Commit-Queue: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583804}

storage/browser/blob/mojo_blob_reader.cc

@@ -39,11 +39,14 @@ MojoBlobReader::MojoBlobReader(const BlobDataHandle* handle,
 }
 
 MojoBlobReader::~MojoBlobReader() {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   TRACE_EVENT_ASYNC_END1("Blob", "BlobReader", this, "bytes_written",
                          total_written_bytes_);
 }
 
 void MojoBlobReader::Start() {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+
   if (blob_reader_->net_error()) {
     NotifyCompletedAndDeleteIfNeeded(blob_reader_->net_error());
     return;
@@ -69,6 +72,8 @@ void MojoBlobReader::Start() {
 }
 
 void MojoBlobReader::NotifyCompletedAndDeleteIfNeeded(int result) {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+
   blob_reader_ = nullptr;
   if (!notified_completed_) {
     delegate_->OnComplete(static_cast<net::Error>(result),
@@ -82,6 +87,8 @@ void MojoBlobReader::NotifyCompletedAndDeleteIfNeeded(int result) {
 }
 
 void MojoBlobReader::DidCalculateSize(int result) {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+
   if (result != net::OK) {
     TRACE_EVENT_ASYNC_END1("Blob", "BlobReader::CountSize", this, "result",
                            "error");
@@ -126,6 +133,8 @@ void MojoBlobReader::DidCalculateSize(int result) {
 }
 
 void MojoBlobReader::DidReadSideData(BlobReader::Status status) {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+
   if (status != BlobReader::Status::DONE) {
     NotifyCompletedAndDeleteIfNeeded(blob_reader_->net_error());
     return;
@@ -135,6 +144,8 @@ void MojoBlobReader::DidReadSideData(BlobReader::Status status) {
 }
 
 void MojoBlobReader::StartReading() {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+
   response_body_stream_ = delegate_->PassDataPipe();
   peer_closed_handle_watcher_.Watch(
       response_body_stream_.get(), MOJO_HANDLE_SIGNAL_PEER_CLOSED,
@@ -152,6 +163,7 @@ void MojoBlobReader::StartReading() {
 }
 
 void MojoBlobReader::ReadMore() {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   DCHECK(!pending_write_.get());
 
   uint32_t num_bytes;
@@ -192,6 +204,8 @@ void MojoBlobReader::ReadMore() {
 }
 
 void MojoBlobReader::DidRead(bool completed_synchronously, int num_bytes) {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+
   if (num_bytes < 0) {
     TRACE_EVENT_ASYNC_END2("Blob", "BlobReader::ReadMore", this, "result",
                            "error", "net_error", num_bytes);
@@ -223,12 +237,16 @@ void MojoBlobReader::DidRead(bool completed_synchronously, int num_bytes) {
 }
 
 void MojoBlobReader::OnResponseBodyStreamClosed(MojoResult result) {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+
   response_body_stream_.reset();
   pending_write_ = nullptr;
   NotifyCompletedAndDeleteIfNeeded(net::ERR_ABORTED);
 }
 
 void MojoBlobReader::OnResponseBodyStreamReady(MojoResult result) {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+
   if (result == MOJO_RESULT_FAILED_PRECONDITION) {
     OnResponseBodyStreamClosed(MOJO_RESULT_OK);
     return;

storage/browser/blob/mojo_blob_reader.h

@@ -7,6 +7,7 @@
 
 #include <memory>
 #include "base/memory/ref_counted.h"
+#include "base/sequence_checker.h"
 #include "mojo/public/cpp/system/data_pipe.h"
 #include "mojo/public/cpp/system/simple_watcher.h"
 #include "net/base/net_errors.h"
@@ -38,7 +39,7 @@ class STORAGE_EXPORT MojoBlobReader {
    public:
     enum RequestSideData { REQUEST_SIDE_DATA, DONT_REQUEST_SIDE_DATA };
 
-    virtual ~Delegate() {}
+    virtual ~Delegate() = default;
 
     // Called when the blob being read has been fully constructed and its size
     // is known. |total_size| is the total size of the blob, while
@@ -99,7 +100,7 @@ class STORAGE_EXPORT MojoBlobReader {
   void OnResponseBodyStreamClosed(MojoResult result);
   void OnResponseBodyStreamReady(MojoResult result);
 
-  std::unique_ptr<Delegate> delegate_;
+  const std::unique_ptr<Delegate> delegate_;
 
   // The range of the blob that should be read. Could be unbounded if the entire
   // blob is being read.
@@ -130,6 +131,8 @@ class STORAGE_EXPORT MojoBlobReader {
   // sure OnComplete isn't called more than once.
   bool notified_completed_ = false;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   base::WeakPtrFactory<MojoBlobReader> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MojoBlobReader);