hg: jdk9/sandbox/jdk: http-client-branch: set of minor performance fixed (make string concat indifyStringConcat friendly, replace synchronized maps to ConcurrentHashMap, LinkedList to ArrayList)

[sergey.kuksenko at oracle.com]

Changeset: c72f3cc1346a
Author:    Sergey Kuksenko <sergey.kuksenko at oracle.com>
Date:      2016-12-02 15:55 -0800
URL:       http://hg.openjdk.java.net/jdk9/sandbox/jdk/rev/c72f3cc1346a

http-client-branch: set of minor performance fixed (make string concat indifyStringConcat friendly, replace synchronized maps to ConcurrentHashMap, LinkedList to ArrayList)

! src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/Http2ClientImpl.java
! src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/Http2Connection.java
! src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/ResponseProcessors.java
! src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/internal/common/HttpHeadersImpl.java