Fix progress reporting for multibuffers to report progress for every byte we receive.

media/blink/multibuffer.cc

 // Copyright 2015 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 <utility>
 
 #include "media/blink/multibuffer.h"
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 371 matching lines @@
       lru_->Use(this, pos);
     ++pos;
   }
   int64_t blocks_after = data_.size();
   int64_t blocks_added = blocks_after - blocks_before;
 
   if (pos > start_pos) {
     present_.SetInterval(start_pos, pos, 1);
     Interval<BlockId> expanded_range = present_.find(start_pos).interval();
     NotifyAvailableRange(expanded_range, expanded_range);
-
     lru_->IncrementDataSize(blocks_added);
     Prune(blocks_added * kMaxFreesPerAdd + 1);
+  } else {
+    // Make sure to give progress reports even when there
+    // aren't any new blocks yet.
+    NotifyAvailableRange(Interval<BlockId>(start_pos, start_pos + 1),
+                         Interval<BlockId>(start_pos, start_pos));
   }
 
   // Check that it's still there before we try to delete it.
   // In case of EOF or a collision, we might not have called AddProvider above.
   // Even if we did call AddProvider, calling NotifyAvailableRange can cause
   // readers to seek or self-destruct and clean up any associated writers.
   auto i = writer_index_.find(pos);
   if (i != writer_index_.end() && i->second.get() == provider_tmp) {
     switch (SuggestProviderState(pos)) {
       case ProviderStateLoad:
@@ skipping 106 matching lines @@
   }
 }
 
 void MultiBuffer::IncrementMaxSize(int32_t size) {
   max_size_ += size;
   lru_->IncrementMaxSize(size);
   DCHECK_GE(max_size_, 0);
   // Pruning only happens when blocks are added.
 }
 
+int64_t MultiBuffer::UncommittedBytesAt(const MultiBuffer::BlockId& block) {
+  auto i = writer_index_.find(block);
+  if (writer_index_.end() == i)
+    return 0;
+  return i->second->AvailableBytes();
+}
+
 }  // namespace media