Introduce a secondary map for enabling plznavigate

android_webview/native/aw_contents_io_thread_client_impl.cc

Index: android_webview/native/aw_contents_io_thread_client_impl.cc
diff --git a/android_webview/native/aw_contents_io_thread_client_impl.cc b/android_webview/native/aw_contents_io_thread_client_impl.cc
index e1bc3490ba12491eaf72ac985384179919192a2e..38ee88f6f44915d2ae429df46c883a3fa72c4295 100644
--- a/android_webview/native/aw_contents_io_thread_client_impl.cc
+++ b/android_webview/native/aw_contents_io_thread_client_impl.cc
@@ -57,6 +57,11 @@ IoThreadClientData::IoThreadClientData() : pending_association(false) {}
 typedef map<pair<int, int>, IoThreadClientData>
     RenderFrameHostToIoThreadClientType;
 
+// When browser side navigation is enabled, RenderFrameIDs do not have
+// valid render process host and render frame ids for frame navigations.
+// We need to identify these by using Frame Tree Node ids.
+typedef map<int, IoThreadClientData> FrameTreeNodeToIoThreadClientType;
+
 static pair<int, int> GetRenderFrameHostIdPair(RenderFrameHost* rfh) {
   return pair<int, int>(rfh->GetProcess()->GetID(), rfh->GetRoutingID());
 }
@@ -69,9 +74,14 @@ class RfhToIoThreadClientMap {
   bool Get(pair<int, int> rfh_id, IoThreadClientData* client);
   void Erase(pair<int, int> rfh_id);
 
+  void Set(int frame_tree_node_id, const IoThreadClientData& client);
+  bool Get(int frame_tree_node_id, IoThreadClientData* client);
+  void Erase(int frame_tree_node_id);
+
  private:
   base::Lock map_lock_;
   RenderFrameHostToIoThreadClientType rfh_to_io_thread_client_;
+  FrameTreeNodeToIoThreadClientType frame_tree_node_to_io_thread_client_;
 };
 
 // static
@@ -110,6 +120,29 @@ void RfhToIoThreadClientMap::Erase(pair<int, int> rfh_id) {
   rfh_to_io_thread_client_.erase(rfh_id);
 }
 
+void RfhToIoThreadClientMap::Set(int frame_tree_node_id,
+                                 const IoThreadClientData& client) {
+  base::AutoLock lock(map_lock_);
+  frame_tree_node_to_io_thread_client_[frame_tree_node_id] = client;
+}
+
+bool RfhToIoThreadClientMap::Get(int frame_tree_node_id,
+                                 IoThreadClientData* client) {
+  base::AutoLock lock(map_lock_);
+  FrameTreeNodeToIoThreadClientType::iterator iterator =
+      frame_tree_node_to_io_thread_client_.find(frame_tree_node_id);
+  if (iterator == frame_tree_node_to_io_thread_client_.end())
+    return false;
+
+  *client = iterator->second;
+  return true;
+}
+
+void RfhToIoThreadClientMap::Erase(int frame_tree_node_id) {
+  base::AutoLock lock(map_lock_);
+  frame_tree_node_to_io_thread_client_.erase(frame_tree_node_id);
+}
+
 // ClientMapEntryUpdater ------------------------------------------------------
 
 class ClientMapEntryUpdater : public content::WebContentsObserver {
@@ -141,12 +174,15 @@ void ClientMapEntryUpdater::RenderFrameCreated(RenderFrameHost* rfh) {
   IoThreadClientData client_data;
   client_data.io_thread_client = jdelegate_;
   client_data.pending_association = false;
-  RfhToIoThreadClientMap::GetInstance()->Set(
-      GetRenderFrameHostIdPair(rfh), client_data);
+  RfhToIoThreadClientMap::GetInstance()->Set(GetRenderFrameHostIdPair(rfh),
+                                             client_data);
+  RfhToIoThreadClientMap::GetInstance()->Set(rfh->GetFrameTreeNodeId(),
+                                             client_data);
 }
 
 void ClientMapEntryUpdater::RenderFrameDeleted(RenderFrameHost* rfh) {
   RfhToIoThreadClientMap::GetInstance()->Erase(GetRenderFrameHostIdPair(rfh));
+  RfhToIoThreadClientMap::GetInstance()->Erase(rfh->GetFrameTreeNodeId());
 }
 
 void ClientMapEntryUpdater::WebContentsDestroyed() {
@@ -175,6 +211,22 @@ std::unique_ptr<AwContentsIoThreadClient> AwContentsIoThreadClient::FromID(
                                        java_delegate));
 }
 
+std::unique_ptr<AwContentsIoThreadClient> AwContentsIoThreadClient::FromID(
+    int frame_tree_node_id) {
+  IoThreadClientData client_data;
+  if (!RfhToIoThreadClientMap::GetInstance()->Get(frame_tree_node_id,
+                                                  &client_data))
+    return std::unique_ptr<AwContentsIoThreadClient>();
+
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jobject> java_delegate =
+      client_data.io_thread_client.get(env);
+  DCHECK(!client_data.pending_association || java_delegate.is_null());
+  return std::unique_ptr<AwContentsIoThreadClient>(
+      new AwContentsIoThreadClientImpl(client_data.pending_association,
+                                       java_delegate));
+}
+
 // static
 void AwContentsIoThreadClient::SubFrameCreated(int render_process_id,
                                                int parent_render_frame_id,