Revert "This CL is to reduce the complexity of current FIFO structure."

third_party/WebKit/Source/platform/audio/AudioPullFIFO.h

Index: third_party/WebKit/Source/platform/audio/AudioPullFIFO.h
diff --git a/third_party/WebKit/Source/platform/audio/AudioPullFIFO.h b/third_party/WebKit/Source/platform/audio/AudioPullFIFO.h
new file mode 100644
index 0000000000000000000000000000000000000000..7f375b2ee596b2b1e8f3ad7ee2a84ddb74345343
--- /dev/null
+++ b/third_party/WebKit/Source/platform/audio/AudioPullFIFO.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2012 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef AudioPullFIFO_h
+#define AudioPullFIFO_h
+
+#include "platform/audio/AudioBus.h"
+#include "platform/audio/AudioFIFO.h"
+#include "platform/audio/AudioSourceProvider.h"
+#include "wtf/Allocator.h"
+
+namespace blink {
+
+// A FIFO (First In First Out) buffer to handle mismatches in buffer sizes
+// between a provider and receiver. The receiver will "pull" data from this
+// FIFO. If data is already available in the FIFO, it is provided to the
+// receiver. If insufficient data is available to satisfy the request, the FIFO
+// will ask the provider for more data when necessary to fulfill a request.
+// Contrast this with a "push" FIFO, where the sender pushes data to the FIFO
+// which will itself push the data to the receiver when the FIFO is full.
+class PLATFORM_EXPORT AudioPullFIFO {
+  USING_FAST_MALLOC(AudioPullFIFO);
+  WTF_MAKE_NONCOPYABLE(AudioPullFIFO);
+
+ public:
+  // Create a FIFO that gets data from |provider|. The FIFO will be large
+  // enough to hold |fifoLength| frames of data of |numberOfChannels| channels.
+  // The AudioSourceProvider will be asked to produce |providerSize| frames
+  // when the FIFO needs more data.
+  AudioPullFIFO(AudioSourceProvider& audioProvider,
+                unsigned numberOfChannels,
+                size_t fifoLength,
+                size_t providerSize);
+
+  // Read |framesToConsume| frames from the FIFO into the destination. If the
+  // FIFO does not have enough data, we ask the |provider| to get more data to
+  // fulfill the request.
+  void consume(AudioBus* destination, size_t framesToConsume);
+
+ private:
+  // Fill the FIFO buffer with at least |numberOfFrames| more data.
+  void fillBuffer(size_t numberOfFrames);
+
+  // The provider of the data in our FIFO.
+  AudioSourceProvider& m_provider;
+
+  // The actual FIFO
+  AudioFIFO m_fifo;
+
+  // Number of frames of data that the provider will produce per call.
+  unsigned m_providerSize;
+
+  // Temporary workspace to hold the data from the provider.
+  RefPtr<AudioBus> m_tempBus;
+};
+
+}  // namespace blink
+
+#endif  // AudioPullFIFO.h