Make FileStream::Seek async and add FileStream::SeekSync for sync operation

net/base/test_completion_callback.cc

Index: net/base/test_completion_callback.cc
diff --git a/net/base/test_completion_callback.cc b/net/base/test_completion_callback.cc
index d68678b8ce8e4f9b7e2020120423776b1b3a8a65..0d4b833684731b1108fed0b8ed89a48a671d779b 100644
--- a/net/base/test_completion_callback.cc
+++ b/net/base/test_completion_callback.cc
@@ -8,16 +8,16 @@
 #include "base/bind_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop.h"
-#include "net/base/net_errors.h"
 
-void TestCompletionCallbackBase::SetResult(int result) {
-  result_ = result;
+namespace internal {
+
+void TestCompletionCallbackBaseInternal::DidSetResult() {
   have_result_ = true;
   if (waiting_for_result_)
     MessageLoop::current()->Quit();
 }
 
-int TestCompletionCallbackBase::WaitForResult() {
+void TestCompletionCallbackBaseInternal::WaitForResult() {
   DCHECK(!waiting_for_result_);
 
   while (!have_result_) {
@@ -25,24 +25,15 @@ int TestCompletionCallbackBase::WaitForResult() {
     MessageLoop::current()->Run();
     waiting_for_result_ = false;
   }
-
-  have_result_ = false;  // Auto-reset for next callback.
-  return result_;
-}
-
-int TestCompletionCallbackBase::GetResult(int result) {
-  if (net::ERR_IO_PENDING != result)
-    return result;
-
-  return WaitForResult();
 }
 
-TestCompletionCallbackBase::TestCompletionCallbackBase()
-    : result_(0),
-      have_result_(false),
+TestCompletionCallbackBaseInternal::TestCompletionCallbackBaseInternal()
+    : have_result_(false),
       waiting_for_result_(false) {
 }
 
+}  // namespace internal
+
 namespace net {
 
 TestCompletionCallback::TestCompletionCallback()
@@ -53,5 +44,12 @@ TestCompletionCallback::TestCompletionCallback()
 
 TestCompletionCallback::~TestCompletionCallback() {}
 
+TestInt64CompletionCallback::TestInt64CompletionCallback()
+    : ALLOW_THIS_IN_INITIALIZER_LIST(callback_(
+        base::Bind(&TestInt64CompletionCallback::SetResult,
+                   base::Unretained(this)))) {
+}
+
+TestInt64CompletionCallback::~TestInt64CompletionCallback() {}
 
 }  // namespace net