1 files changed, 17 insertions, 5 deletions
diff --git a/content/browser/loader/resource_loader.cc b/content/browser/loader/resource_loader.cc
index 6bab366..fde1697 100644
--- a/content/browser/loader/resource_loader.cc
+++ b/content/browser/loader/resource_loader.cc
@@ -355,14 +355,23 @@ void ResourceLoader::OnReadCompleted(net::URLRequest* unused, int bytes_read) {
     return;
   }
 
-  CompleteRead(bytes_read);
-
-  if (is_deferred())
+  // If the handler cancelled or deferred the request, do not continue
+  // processing the read. If cancelled, the URLRequest has already been
+  // cancelled and will schedule an erroring OnReadCompleted later. If deferred,
+  // do nothing until resumed.
+  //
+  // Note: if bytes_read is 0 (EOF) and the handler defers, resumption will call
+  // Read() on the URLRequest again and get a second EOF.
+  if (!CompleteRead(bytes_read))
     return;
 
-  if (request_->status().is_success() && bytes_read > 0) {
+  DCHECK(request_->status().is_success());
+  DCHECK(!is_deferred());
+  if (bytes_read > 0) {
     StartReading(true);  // Read the next chunk.
   } else {
+    // URLRequest reported an EOF. Call ResponseCompleted.
+    DCHECK_EQ(0, bytes_read);
     ResponseCompleted();
   }
 }
@@ -603,7 +612,7 @@ void ResourceLoader::ReadMore(int* bytes_read) {
   // inspecting the URLRequest's status.
 }
 
-void ResourceLoader::CompleteRead(int bytes_read) {
+bool ResourceLoader::CompleteRead(int bytes_read) {
   DCHECK(bytes_read >= 0);
   DCHECK(request_->status().is_success());
 
@@ -612,9 +621,12 @@ void ResourceLoader::CompleteRead(int bytes_read) {
   bool defer = false;
   if (!handler_->OnReadCompleted(info->GetRequestID(), bytes_read, &defer)) {
     Cancel();
+    return false;
   } else if (defer) {
     deferred_stage_ = DEFERRED_READ;  // Read next chunk when resumed.
+    return false;
   }
+  return true;
 }
 
 void ResourceLoader::ResponseCompleted() {