adb: implement std::make_unique, start using it.

Add an implementation of std::make_unique for Windows, where we're
currently stuck with C++11, and switch some uses of new over to it.

Test: treehugger
Change-Id: I99b85f07754adda7c525243480c3e0bce9a25ce7
diff --git a/adb/fdevent_test.cpp b/adb/fdevent_test.cpp
index 63cc4d1..dadae5a 100644
--- a/adb/fdevent_test.cpp
+++ b/adb/fdevent_test.cpp
@@ -99,7 +99,7 @@
 
     std::vector<std::unique_ptr<FdHandler>> fd_handlers;
     for (size_t i = 0; i < read_fds.size(); ++i) {
-        fd_handlers.push_back(std::unique_ptr<FdHandler>(new FdHandler(read_fds[i], write_fds[i])));
+        fd_handlers.push_back(std::make_unique<FdHandler>(read_fds[i], write_fds[i]));
     }
 
     fdevent_loop();