Move quic_bug_tracker to quic/platform. No functional change expected.

net/net.gypi

Index: net/net.gypi
diff --git a/net/net.gypi b/net/net.gypi
index bf64a2d0470b6a76799617046d23885cddbd77c0..7bd2ca70accd178d33a967787178845e98e32e45 100644
--- a/net/net.gypi
+++ b/net/net.gypi
@@ -1109,7 +1109,6 @@
       'quic/core/quic_buffer_allocator.h',
       'quic/core/quic_buffered_packet_store.cc',
       'quic/core/quic_buffered_packet_store.h',
-      'quic/core/quic_bug_tracker.h',
       'quic/core/quic_client_promised_info.cc',
       'quic/core/quic_client_promised_info.h',
       'quic/core/quic_client_push_promise_index.cc',
@@ -1211,6 +1210,7 @@
       'quic/core/spdy_utils.cc',
       'quic/core/spdy_utils.h',
       'quic/platform/api/quic_aligned.h',
+      'quic/platform/api/quic_bug_tracker.h',
       'quic/platform/api/quic_clock.cc',
       'quic/platform/api/quic_clock.h',
       'quic/platform/api/quic_export.h',
@@ -1226,6 +1226,7 @@
       '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_bug_tracker_impl.h',
       'quic/platform/impl/quic_chromium_clock.cc',
       'quic/platform/impl/quic_chromium_clock.h',
       'quic/platform/impl/quic_export_impl.h',