adb: make fdevent_test, socket_test compile on Windows.

Switch pthread_* to use the adb_thread_* abstractions to allow the fdevent
and socket tests to compile on Win32.

Bug: http://b/27105824
Change-Id: I6541bb1398780b999837e701837d7f86a5eee8ca
(cherry picked from commit 022d447e9efcff59e22f0ab13764282116f235dd)
diff --git a/adb/Android.mk b/adb/Android.mk
index 7835d9f..e0997ea 100644
--- a/adb/Android.mk
+++ b/adb/Android.mk
@@ -59,6 +59,8 @@
 LIBADB_TEST_SRCS := \
     adb_io_test.cpp \
     adb_utils_test.cpp \
+    fdevent_test.cpp \
+    socket_test.cpp \
     sysdeps_test.cpp \
     transport_test.cpp \
 
@@ -87,14 +89,6 @@
     sysdeps_win32.cpp \
     usb_windows.cpp \
 
-LIBADB_TEST_linux_SRCS := \
-    fdevent_test.cpp \
-    socket_test.cpp \
-
-LIBADB_TEST_darwin_SRCS := \
-    fdevent_test.cpp \
-    socket_test.cpp \
-
 LIBADB_TEST_windows_SRCS := \
     sysdeps_win32_test.cpp \