Fix a timing bug in multibuffer.

media/blink/multibuffer_data_source.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 "media/blink/multibuffer_data_source.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 398 matching lines @@
       // fail like they would if we had known the file size at the beginning.
       total_bytes_ = reader_->Tell();
       if (total_bytes_ != kPositionNotSpecified)
         host_->SetTotalBytes(total_bytes_);
     }
 
     ReadOperation::Run(std::move(read_op_), bytes_read);
   } else {
     reader_->Wait(1, base::Bind(&MultibufferDataSource::ReadTask,
                                 weak_factory_.GetWeakPtr()));
-    UpdateLoadingState(false);
+    UpdateLoadingState_Locked(false);
   }
 }
 
 void MultibufferDataSource::StopInternal_Locked() {
   lock_.AssertAcquired();
   if (stop_signal_received_)
     return;
 
   stop_signal_received_ = true;
 
@@ skipping 70 matching lines @@
                                    DidPassCORSAccessCheck());
     media_log_->SetBooleanProperty("range_header_supported",
                                    url_data_->range_supported());
   }
 
   render_task_runner_->PostTask(
       FROM_HERE, base::Bind(base::ResetAndReturn(&init_cb_), success));
 
   // Even if data is cached, say that we're loading at this point for
   // compatibility.
-  UpdateLoadingState(true);
+  UpdateLoadingState_Locked(true);
 }
 
 void MultibufferDataSource::ProgressCallback(int64_t begin, int64_t end) {
   DVLOG(1) << __func__ << "(" << begin << ", " << end << ")";
   DCHECK(render_task_runner_->BelongsToCurrentThread());
 
   if (assume_fully_buffered())
     return;
 
+  base::AutoLock auto_lock(lock_);
+
   if (end > begin) {
     // TODO(scherkus): we shouldn't have to lock to signal host(), see
     // http://crbug.com/113712 for details.
-    base::AutoLock auto_lock(lock_);
     if (stop_signal_received_)
       return;
 
     host_->AddBufferedByteRange(begin, end);
   }
 
-  UpdateLoadingState(false);
+  UpdateLoadingState_Locked(false);
 }
 
-void MultibufferDataSource::UpdateLoadingState(bool force_loading) {
+void MultibufferDataSource::UpdateLoadingState_Locked(bool force_loading) {
   DVLOG(1) << __func__;
+  lock_.AssertAcquired();
   if (assume_fully_buffered())
     return;
   // Update loading state.
   bool is_loading = !!reader_ && reader_->IsLoading();
+  if (read_op_)
+    is_loading = true;
   if (force_loading || is_loading != loading_) {
     loading_ = is_loading || force_loading;
 
     if (!loading_ && cancel_on_defer_) {
       reader_.reset(nullptr);
     }
 
     // Callback could kill us, be sure to call it last.
     downloading_cb_.Run(loading_);
   }
@@ skipping 48 matching lines @@
   reader_->SetPinRange(back_buffer, kMaxBufferPreload + kPreloadHighExtra);
 
   if (preload_ == METADATA) {
     reader_->SetPreload(0, 0);
   } else {
     reader_->SetPreload(preload_high, preload);
   }
 }
 
 }  // namespace media