Update MimeSniffingResourceHandler tests to use MockResourceLoader.

This will make it easier to land an upcoming ResourceHandler refactor,
and also gives us some more ASSERTs shared with other tests. Also add
checking of the error code the request is canceled with.

Also prevent next ResourceHandler in the chain from being called
re-entrantly

BUG=659317

Review-Url: https://codereview.chromium.org/2626663002
Cr-Commit-Position: refs/heads/master@{#443360}

content/browser/loader/mime_sniffing_resource_handler.cc

@@ -245,8 +245,11 @@ void MimeSniffingResourceHandler::Resume() {
   }
 
   // Otherwise proceed with the replay of the response. If it is successful,
-  // it will resume the request.
-  AdvanceState();
+  // it will resume the request. Posted as a task to avoid re-entrancy into
+  // the calling class.
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(&MimeSniffingResourceHandler::AdvanceState,
+                            weak_ptr_factory_.GetWeakPtr()));
 }
 
 void MimeSniffingResourceHandler::Cancel() {

content/browser/loader/mock_resource_loader.cc

@@ -35,6 +35,11 @@ MockResourceLoader::Status MockResourceLoader::OnWillStart(const GURL& url) {
   EXPECT_TRUE(status_ == Status::CALLING_HANDLER ||
               (result == false && status_ == Status::CANCELED));
   if (!result) {
+    // In the case of double-cancels, keep the old error code.
+    // TODO(mmenke):  Once there are no more double cancel cases, remove this
+    // code.
+    if (status_ != Status::CANCELED)
+      error_code_ = net::ERR_ABORTED;
     status_ = Status::CANCELED;
   } else if (defer) {
     status_ = Status::CALLBACK_PENDING;
@@ -61,6 +66,9 @@ MockResourceLoader::Status MockResourceLoader::OnRequestRedirected(
   EXPECT_TRUE(status_ == Status::CALLING_HANDLER ||
               (result == false && status_ == Status::CANCELED));
   if (!result) {
+    // In the case of double-cancels, keep the old error code.
+    if (status_ != Status::CANCELED)
+      error_code_ = net::ERR_ABORTED;
     status_ = Status::CANCELED;
   } else if (defer) {
     status_ = Status::CALLBACK_PENDING;
@@ -85,6 +93,9 @@ MockResourceLoader::Status MockResourceLoader::OnResponseStarted(
   EXPECT_TRUE(status_ == Status::CALLING_HANDLER ||
               (result == false && status_ == Status::CANCELED));
   if (!result) {
+    // In the case of double-cancels, keep the old error code.
+    if (status_ != Status::CANCELED)
+      error_code_ = net::ERR_ABORTED;
     status_ = Status::CANCELED;
   } else if (defer) {
     status_ = Status::CALLBACK_PENDING;
@@ -108,6 +119,9 @@ MockResourceLoader::Status MockResourceLoader::OnWillRead(int min_size) {
   EXPECT_TRUE(status_ == Status::CALLING_HANDLER ||
               (result == false && status_ == Status::CANCELED));
   if (!result) {
+    // In the case of double-cancels, keep the old error code.
+    if (status_ != Status::CANCELED)
+      error_code_ = net::ERR_ABORTED;
     EXPECT_EQ(0, io_buffer_size_);
     EXPECT_FALSE(io_buffer_);
     status_ = Status::CANCELED;
@@ -138,6 +152,9 @@ MockResourceLoader::Status MockResourceLoader::OnReadCompleted(
   EXPECT_TRUE(status_ == Status::CALLING_HANDLER ||
               (result == false && status_ == Status::CANCELED));
   if (!result) {
+    // In the case of double-cancels, keep the old error code.
+    if (status_ != Status::CANCELED)
+      error_code_ = net::ERR_ABORTED;
     status_ = Status::CANCELED;
   } else if (defer) {
     status_ = Status::CALLBACK_PENDING;

content/browser/loader/resource_controller.h

@@ -19,6 +19,10 @@ class CONTENT_EXPORT ResourceController {
   virtual void Cancel() = 0;
   virtual void CancelAndIgnore() = 0;
   virtual void CancelWithError(int error_code) = 0;
+
+  // Resumes the request. May only be called if the request was previously
+  // deferred. Guaranteed not to call back into the ResourceHandler, or destroy
+  // it, synchronously.
   virtual void Resume() = 0;
 
  protected:

content/browser/loader/test_resource_handler.cc

@@ -132,11 +132,14 @@ bool TestResourceHandler::OnWillRead(scoped_refptr<net::IOBuffer>* buf,
 
   ++on_will_read_called_;
 
-  *buf = buffer_;
-  *buf_size = buffer_size_;
-  memset(buffer_->data(), '\0', buffer_size_);
-  if (!on_will_read_result_)
+  if (!on_will_read_result_) {
     canceled_ = true;
+  } else {
+    *buf = buffer_;
+    *buf_size = buffer_size_;
+    memset(buffer_->data(), '\0', buffer_size_);
+  }
+
   return on_will_read_result_;
 }