net: Make UploadDataStream::Init() asynchronous.

net/base/upload_data_stream.h

Index: net/base/upload_data_stream.h
diff --git a/net/base/upload_data_stream.h b/net/base/upload_data_stream.h
index 3d060f97cfad65ea236db0bbf7db10809ab2a235..81ab9e445f516859f10589fe579dfcd45569081c 100644
--- a/net/base/upload_data_stream.h
+++ b/net/base/upload_data_stream.h
@@ -6,6 +6,7 @@
 #define NET_BASE_UPLOAD_DATA_STREAM_H_
 
 #include "base/memory/ref_counted.h"
+#include "net/base/completion_callback.h"
 #include "net/base/net_export.h"
 #include "net/base/upload_data.h"
 
@@ -19,14 +20,27 @@ class NET_EXPORT UploadDataStream {
   explicit UploadDataStream(UploadData* upload_data);
   ~UploadDataStream();
 
-  // Initializes the stream. This function must be called exactly once,
-  // before calling any other method. It is not valid to call any method
-  // (other than the destructor) if Init() returns a failure.
+  // Initializes the stream synchronously or asynchronously depending on
+  // whether the upload data is in memory or not. This function must be called
+  // exactly once, before calling any other method. It is not valid to call any
+  // method (other than the destructor) if the initialization failed.
   //
-  // Returns OK on success. Returns ERR_UPLOAD_FILE_CHANGED if the expected
-  // file modification time is set (usually not set, but set for sliced
-  // files) and the target file is changed.
-  int Init();
+  // If the upload data is in memory, the initialization is done synchronously.
+  // Returns OK or some other error code.
+  //
+  // If initialization requires file IO, returns ERR_IO_PENDING, and runs
+  // |callback| with a result code on the original thread once the
+  // initialization is done.
+  //
+  // ERR_UPLOAD_FILE_CHANGED is passed to |callback| if the expected file
+  // modification time is set (usually not set, but set for sliced files) and
+  // the target file is changed.
+  int Init(const CompletionCallback& callback);
+
+  // Similar to Init() but performs the operation always synchronously. This
+  // version may perform file IO on the current thread. Usually used for
+  // testing, but Chrome Frame also uses this version.
+  int InitSync();
 
   // Reads up to |buf_len| bytes from the upload data stream to |buf|. The
   // number of bytes read is returned. Partial reads are allowed.  Zero is
@@ -74,6 +88,11 @@ class NET_EXPORT UploadDataStream {
   static void ResetMergeChunks();
   static void set_merge_chunks(bool merge) { merge_chunks_ = merge; }
 
+  // Called when InitInternal() is completed. Used to implement Init().
+  void OnInitComplete(const CompletionCallback& callback,
+                      uint64* content_length,
+                      int* result);
+
   scoped_refptr<UploadData> upload_data_;
 
   // Index of the current upload element (i.e. the element currently being
@@ -92,6 +111,8 @@ class NET_EXPORT UploadDataStream {
   // requests with chunked uploads.
   static bool merge_chunks_;
 
+  base::WeakPtrFactory<UploadDataStream> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(UploadDataStream);
 };