Build out backoff as a library
diff --git a/BUILD b/BUILD
index 0e9f37a..bb7b24c 100644
--- a/BUILD
+++ b/BUILD
@@ -45,6 +45,7 @@
name = "gpr",
srcs = [
"src/core/profiling/timers.h",
+ "src/core/support/backoff.h",
"src/core/support/block_annotate.h",
"src/core/support/env.h",
"src/core/support/load_file.h",
@@ -59,6 +60,7 @@
"src/core/profiling/stap_timers.c",
"src/core/support/alloc.c",
"src/core/support/avl.c",
+ "src/core/support/backoff.c",
"src/core/support/cmdline.c",
"src/core/support/cpu_iphone.c",
"src/core/support/cpu_linux.c",
@@ -1162,6 +1164,7 @@
"src/core/profiling/stap_timers.c",
"src/core/support/alloc.c",
"src/core/support/avl.c",
+ "src/core/support/backoff.c",
"src/core/support/cmdline.c",
"src/core/support/cpu_iphone.c",
"src/core/support/cpu_linux.c",
@@ -1246,6 +1249,7 @@
"include/grpc/impl/codegen/sync_win32.h",
"include/grpc/impl/codegen/time.h",
"src/core/profiling/timers.h",
+ "src/core/support/backoff.h",
"src/core/support/block_annotate.h",
"src/core/support/env.h",
"src/core/support/load_file.h",