Add a new QUIC platform API for text utilities.

net/net.gypi

Index: net/net.gypi
diff --git a/net/net.gypi b/net/net.gypi
index c83e8eb876596bac22c86bb11d9d70ae459a2429..8774c56fd7160060dd62d9fe55d3419ff5e7b447 100644
--- a/net/net.gypi
+++ b/net/net.gypi
@@ -1219,6 +1219,7 @@
       'quic/platform/api/quic_socket_address.cc',
       'quic/platform/api/quic_socket_address.h',
       'quic/platform/api/quic_str_cat.h',
+      'quic/platform/api/quic_text_utils.h',
       'quic/platform/impl/quic_aligned_impl.h',
       'quic/platform/impl/quic_chromium_clock.cc',
       'quic/platform/impl/quic_chromium_clock.h',
@@ -1232,6 +1233,7 @@
       'quic/platform/impl/quic_socket_address_impl.cc',
       'quic/platform/impl/quic_socket_address_impl.h',
       'quic/platform/impl/quic_str_cat_impl.h',
+      'quic/platform/impl/quic_text_utils_impl.h',
       'quic/quartc/quartc_alarm_factory.cc',
       'quic/quartc/quartc_alarm_factory.h',
       'quic/quartc/quartc_factory.cc',
@@ -1968,6 +1970,7 @@
       'quic/platform/api/quic_lru_cache_test.cc',
       'quic/platform/api/quic_reference_counted_test.cc',
       'quic/platform/api/quic_str_cat_test.cc',
+      'quic/platform/api/quic_text_utils_test.cc',
       'quic/platform/impl/quic_chromium_clock_test.cc',
       'quic/quartc/quartc_alarm_factory_test.cc',
       'quic/quartc/quartc_session_test.cc',