Change Http2PriorityDependencies to refer to parent_stream_id

instead of dependent_stream_id to match the language in the HTTP spec
and to make it clear which direction the dependency points.

Change-Id: I715b9f87a8ca614efd7d816c9f4229c52747e142
Reviewed-on: https://chromium-review.googlesource.com/917203
Commit-Queue: Ryan Hamilton <rch@chromium.org>
Reviewed-by: Randy Smith <rdsmith@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537538}

net/quic/chromium/quic_chromium_client_session.cc

@@ -912,9 +912,10 @@ void QuicChromiumClientSession::UpdateStreamPriority(
     for (auto update : updates) {
       QuicSpdyStream* stream = GetSpdyDataStream(update.id);
       DCHECK(stream);
-      SpdyPriority priority = stream->QuicSpdyStream::priority();
-      WritePriority(update.id, update.dependent_stream_id,
-                    Spdy3PriorityToHttp2Weight(priority), update.exclusive);
+      int weight =
+          Spdy3PriorityToHttp2Weight(stream->QuicSpdyStream::priority());
+      WritePriority(update.id, update.parent_stream_id, weight,
+                    update.exclusive);
     }
   }
   QuicSpdySession::UpdateStreamPriority(id, new_priority);

net/spdy/chromium/http2_priority_dependencies.cc

@@ -11,16 +11,15 @@ Http2PriorityDependencies::Http2PriorityDependencies() = default;
 
 Http2PriorityDependencies::~Http2PriorityDependencies() = default;
 
-void Http2PriorityDependencies::OnStreamCreation(
-    SpdyStreamId id,
-    SpdyPriority priority,
-    SpdyStreamId* dependent_stream_id,
-    int* weight,
-    bool* exclusive) {
+void Http2PriorityDependencies::OnStreamCreation(SpdyStreamId id,
+                                                 SpdyPriority priority,
+                                                 SpdyStreamId* parent_stream_id,
+                                                 int* weight,
+                                                 bool* exclusive) {
   if (entry_by_stream_id_.find(id) != entry_by_stream_id_.end())
     return;
 
-  *dependent_stream_id = 0;
+  *parent_stream_id = 0;
   *exclusive = true;
   // Since the generated dependency graph is a single linked list, the value
   // of weight should not actually matter, and perhaps the default weight of 16
@@ -33,7 +32,7 @@ void Http2PriorityDependencies::OnStreamCreation(
   // Dependent on the lowest-priority stream that has a priority >= |priority|.
   IdList::iterator parent;
   if (PriorityLowerBound(priority, &parent)) {
-    *dependent_stream_id = parent->first;
+    *parent_stream_id = parent->first;
   }
 
   id_priority_lists_[priority].push_back(std::make_pair(id, priority));

net/spdy/chromium/http2_priority_dependencies.h

@@ -29,13 +29,13 @@ class NET_EXPORT_PRIVATE Http2PriorityDependencies {
 
   // Called when a stream is created. This is used for both client-initiated
   // and server-initiated (pushed) streams.
-  // On return, |*dependent_stream_id| is set to the stream id that
-  // this stream should be made dependent on, |*exclusive| is set to
-  // whether that dependency should be exclusive, and |*weight| is set to
-  // the relative weight for the created stream given this priority.
+  // On return, |*parent_stream_id| is set to the stream id that should become
+  // the parent of this stream, |*exclusive| is set to whether that dependency
+  // should be exclusive, and |*weight| is set to the relative weight for the
+  // created stream given this priority.
   void OnStreamCreation(SpdyStreamId id,
                         SpdyPriority priority,
-                        SpdyStreamId* dependent_stream_id,
+                        SpdyStreamId* parent_stream_id,
                         int* weight,
                         bool* exclusive);
 
@@ -44,7 +44,7 @@ class NET_EXPORT_PRIVATE Http2PriorityDependencies {
 
   struct DependencyUpdate {
     SpdyStreamId id;
-    SpdyStreamId dependent_stream_id;
+    SpdyStreamId parent_stream_id;
     bool exclusive;
   };
 

net/spdy/chromium/http2_priority_dependencies_unittest.cc

@@ -15,7 +15,7 @@ namespace net {
 
 bool operator==(const Http2PriorityDependencies::DependencyUpdate& a,
                 const Http2PriorityDependencies::DependencyUpdate& b) {
-  return a.id == b.id && a.dependent_stream_id == b.dependent_stream_id &&
+  return a.id == b.id && a.parent_stream_id == b.parent_stream_id &&
          a.exclusive == b.exclusive;
 }
 
@@ -23,7 +23,7 @@ std::ostream& operator<<(
     std::ostream& os,
     const std::vector<Http2PriorityDependencies::DependencyUpdate>& v) {
   for (auto e : v) {
-    os << "{" << e.id << "," << e.dependent_stream_id << ","
+    os << "{" << e.id << "," << e.parent_stream_id << ","
        << (e.exclusive ? "true" : "false") << "}";
   }
   return os;
@@ -45,21 +45,21 @@ class HttpPriorityDependencyTest : public PlatformTest {
 
   void TestStreamCreation(SpdyStreamId new_id,
                           SpdyPriority priority,
-                          SpdyStreamId expected_dependent_id) {
+                          SpdyStreamId expected_parent_id) {
     int expected_weight = Spdy3PriorityToHttp2Weight(priority);
 
-    SpdyStreamId dependent_id = 999u;
+    SpdyStreamId parent_id = 999u;
     int weight = -1;
     bool exclusive = false;
-    dependency_state_.OnStreamCreation(new_id, priority, &dependent_id, &weight,
+    dependency_state_.OnStreamCreation(new_id, priority, &parent_id, &weight,
                                        &exclusive);
-    if (expected_dependent_id != dependent_id || !exclusive ||
+    if (expected_parent_id != parent_id || !exclusive ||
         expected_weight != weight) {
       ADD_FAILURE() << "OnStreamCreation(" << new_id << ", " << int(priority)
                     << ")\n"
-                    << "  Got:  (" << dependent_id << ", " << weight << ", "
+                    << "  Got:  (" << parent_id << ", " << weight << ", "
                     << exclusive << ")\n"
-                    << "  Want: (" << expected_dependent_id << ", "
+                    << "  Want: (" << expected_parent_id << ", "
                     << expected_weight << ", true)\n";
     }
   }

net/spdy/chromium/spdy_session.cc

@@ -868,7 +868,7 @@ int SpdySession::GetPushedStream(const GURL& url,
     DCHECK(it != active_streams_.end());
     int weight = Spdy3PriorityToHttp2Weight(
         ConvertRequestPriorityToSpdyPriority(it->second->priority()));
-    EnqueuePriorityFrame(u.id, u.dependent_stream_id, weight, u.exclusive);
+    EnqueuePriorityFrame(u.id, u.parent_stream_id, weight, u.exclusive);
   }
 
   return OK;
@@ -967,24 +967,24 @@ std::unique_ptr<SpdySerializedFrame> SpdySession::CreateHeaders(
 
   bool has_priority = true;
   int weight = 0;
-  SpdyStreamId dependent_stream_id = 0;
+  SpdyStreamId parent_stream_id = 0;
   bool exclusive = false;
 
   priority_dependency_state_.OnStreamCreation(
-      stream_id, spdy_priority, &dependent_stream_id, &weight, &exclusive);
+      stream_id, spdy_priority, &parent_stream_id, &weight, &exclusive);
 
   if (net_log().IsCapturing()) {
     net_log().AddEvent(
         NetLogEventType::HTTP2_SESSION_SEND_HEADERS,
         base::Bind(&NetLogSpdyHeadersSentCallback, &block,
                    (flags & CONTROL_FLAG_FIN) != 0, stream_id, has_priority,
-                   weight, dependent_stream_id, exclusive, source_dependency));
+                   weight, parent_stream_id, exclusive, source_dependency));
   }
 
   SpdyHeadersIR headers(stream_id, std::move(block));
   headers.set_has_priority(has_priority);
   headers.set_weight(weight);
-  headers.set_parent_stream_id(dependent_stream_id);
+  headers.set_parent_stream_id(parent_stream_id);
   headers.set_exclusive(exclusive);
   headers.set_fin((flags & CONTROL_FLAG_FIN) != 0);