Fix a timing bug in multibuffer.

media/blink/multibuffer_data_source_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 299 matching lines @@
   }
 
   void Respond(const WebURLResponse& response) {
     EXPECT_TRUE(url_loader());
     if (!active_loader())
       return;
     data_provider()->didReceiveResponse(url_loader(), response);
     base::RunLoop().RunUntilIdle();
   }
 
-  void ReceiveData(int size) {
+  void ReceiveDataLow(int size) {
     EXPECT_TRUE(url_loader());
     if (!url_loader())
       return;
     std::unique_ptr<char[]> data(new char[size]);
     memset(data.get(), 0xA5, size);  // Arbitrary non-zero value.
 
     data_provider()->didReceiveData(url_loader(), data.get(), size, size, size);
+  }
+
+  void ReceiveData(int size) {
+    ReceiveDataLow(size);
     base::RunLoop().RunUntilIdle();
   }
 
   void FinishLoading() {
     EXPECT_TRUE(url_loader());
     if (!url_loader())
       return;
     data_provider()->didFinishLoading(url_loader(), 0, -1);
     base::RunLoop().RunUntilIdle();
   }
@@ skipping 914 matching lines @@
   data_source_->OnBufferingHaveEnough(false);
   ASSERT_TRUE(active_loader());
 
   EXPECT_CALL(*this, ReadCallback(kDataSize));
   EXPECT_CALL(host_, AddBufferedByteRange(0, kDataSize * 2));
   ReceiveData(kDataSize);
 
   EXPECT_FALSE(active_loader_allownull());
 }
 
+// This test tries to trigger an edge case where the read callback
+// never happens because the reader is deleted before that happens.
+TEST_F(MultibufferDataSourceTest,
+       ExternalResource_Response206_CancelAfterDefer2) {
+  set_preload(MultibufferDataSource::METADATA);
+  InitializeWith206Response();
+
+  EXPECT_EQ(MultibufferDataSource::METADATA, preload());
+  EXPECT_FALSE(is_local_source());
+
+  EXPECT_TRUE(data_source_->range_supported());
+  CheckReadThenDefer();
+
+  ReadAt(kDataSize);
+
+  data_source_->OnBufferingHaveEnough(false);
+  ASSERT_TRUE(active_loader());
+
+  EXPECT_CALL(*this, ReadCallback(kDataSize));
+  EXPECT_CALL(host_, AddBufferedByteRange(kDataSize, kDataSize + 2000));
+
+  ReceiveDataLow(2000);
+  EXPECT_CALL(host_, AddBufferedByteRange(0, kDataSize * 2 + 2000));
+  ReceiveDataLow(kDataSize);
+
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_FALSE(active_loader_allownull());
+}
+
 TEST_F(MultibufferDataSourceTest,
        ExternalResource_Response206_CancelAfterPlay) {
   set_preload(MultibufferDataSource::METADATA);
   InitializeWith206Response();
 
   EXPECT_EQ(MultibufferDataSource::METADATA, preload());
   EXPECT_FALSE(is_local_source());
 
   EXPECT_TRUE(data_source_->range_supported());
   CheckReadThenDefer();
@@ skipping 215 matching lines @@
   const std::string etag("\"arglebargle glop-glyf?\"");
   response.setHTTPHeaderField(WebString::fromUTF8("Etag"),
                               WebString::fromUTF8(etag));
   Respond(response);
   EXPECT_CALL(host_, AddBufferedByteRange(0, kDataSize));
   ReceiveData(kDataSize);
 
   EXPECT_EQ(url_data()->etag(), etag);
 }
 }  // namespace media