[PM] Migrate BoostingVoteAggregator to VotingChannelWrapper.

Bug: 971272
Change-Id: I8beac0e036d84884e4c13a2b7d84c4d8b2d1ce6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2533535
Commit-Queue: Patrick Monette <pmonette@chromium.org>
Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828604}

components/performance_manager/execution_context_priority/boosting_vote_aggregator.cc

@@ -256,10 +256,7 @@ VotingChannel BoostingVoteAggregator::GetVotingChannel() {
 }
 
 void BoostingVoteAggregator::SetUpstreamVotingChannel(VotingChannel&& channel) {
-  DCHECK(channel.IsValid());
-  DCHECK(nodes_.empty());
-  DCHECK(!channel_.IsValid());
-  channel_ = std::move(channel);
+  channel_.SetVotingChannel(std::move(channel));
 }
 
 bool BoostingVoteAggregator::IsSetup() const {
@@ -549,8 +546,10 @@ void BoostingVoteAggregator::UpstreamVoteIfNeeded(
   // default priority level of every execution context in the absence of any
   // specific higher votes.
   if (priority == base::TaskPriority::LOWEST) {
-    if (node_data->HasOutgoingVote())
+    if (node_data->HasOutgoingVote()) {
+      channel_.InvalidateVote(execution_context);
       node_data->CancelOutgoingVote();
+    }
     return;
   }
 
@@ -560,13 +559,13 @@ void BoostingVoteAggregator::UpstreamVoteIfNeeded(
   // If the node already has a vote, then change it. This is a nop if the vote
   // details are identical.
   if (node_data->HasOutgoingVote()) {
-    node_data->ChangeOutgoingVote(priority, reason);
+    channel_.ChangeVote(execution_context, Vote(priority, reason));
     return;
   }
 
   // Create an outgoing vote.
-  node_data->SetOutgoingVoteReceipt(
-      channel_.SubmitVote(execution_context, Vote(priority, reason)));
+  node_data->SetHasOutgoingVote();
+  channel_.SubmitVote(execution_context, Vote(priority, reason));
 }
 
 void BoostingVoteAggregator::UpstreamChanges(const NodeDataPtrSet& changes) {

components/performance_manager/public/execution_context_priority/boosting_vote_aggregator.h

@@ -128,7 +128,6 @@ class BoostingVoteAggregator : public VoteObserver {
     ~NodeData();
 
     const Vote& incoming_vote() const { return incoming_vote_.value(); }
-    const VoteReceipt& receipt() const { return receipt_; }
 
     void SetIncomingVote(const Vote& incoming_vote) {
       DCHECK(!incoming_vote_.has_value());
@@ -143,13 +142,13 @@ class BoostingVoteAggregator : public VoteObserver {
       incoming_vote_ = base::nullopt;
     }
 
-    // For modifying |receipt_|.
-    void ChangeOutgoingVote(base::TaskPriority priority, const char* reason) {
-      receipt_.ChangeVote(priority, reason);
+    void CancelOutgoingVote() {
+      DCHECK(has_outgoing_vote_);
+      has_outgoing_vote_ = false;
     }
-    void CancelOutgoingVote() { receipt_.Reset(); }
-    void SetOutgoingVoteReceipt(VoteReceipt&& receipt) {
-      receipt_ = std::move(receipt);
+    void SetHasOutgoingVote() {
+      DCHECK(!has_outgoing_vote_);
+      has_outgoing_vote_ = true;
     }
 
     // Returns true if this node has an active |incoming| vote. If false that
@@ -157,9 +156,8 @@ class BoostingVoteAggregator : public VoteObserver {
     // Same as |incoming_vote_.has_value()|, but more readable.
     bool HasIncomingVote() const { return incoming_vote_.has_value(); }
 
-    // Returns true if this node has an active outgoing vote. Same as
-    // |receipt_.HasVote()|, but more readable.
-    bool HasOutgoingVote() const { return receipt_.HasVote(); }
+    // Returns true if this node has an active outgoing vote.
+    bool HasOutgoingVote() const { return has_outgoing_vote_; }
 
     // Returns true if this node is involved in any edges.
     bool HasEdges() const { return edge_count_ > 0; }
@@ -183,8 +181,9 @@ class BoostingVoteAggregator : public VoteObserver {
     // The input vote we've received, if any.
     base::Optional<Vote> incoming_vote_;
 
-    // The receipt for the vote we've upstreamed, if any.
-    VoteReceipt receipt_;
+    // Indicates that a corresponding vote has been emitted via the
+    // voting channel.
+    bool has_outgoing_vote_ = false;
   };
 
   // NOTE: It is important that NodeDataMap preserve pointers to NodeData
@@ -371,7 +370,7 @@ class BoostingVoteAggregator : public VoteObserver {
   voting::VoterId<Vote> input_voter_id_ = voting::kInvalidVoterId<Vote>;
 
   // Our channel for upstreaming our votes.
-  VotingChannel channel_;
+  VotingChannelWrapper channel_;
 
   // Provides a VotingChannel to our input voter.
   VoteConsumerDefaultImpl vote_consumer_default_impl_;