Include the implemented header first in all projects.

The Google C++ style guide dictates that foo.cc and foo_unittest.cc
should include foo.h in the first place, so missing headers in foo.h
are detected with a compile error of the module implementing them and
not when another module uses them.

This CL sweeps across all the .cc file in platform2 enforcing this.

BUG=None
TEST=cbuildbot amd64-generic

Change-Id: I41835835caba13f54c3c844ecf552eb0e47efa9d
Reviewed-on: https://chromium-review.googlesource.com/228894
Tested-by: Alex Deymo <deymo@chromium.org>
Reviewed-by: Alex Deymo <deymo@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/metrics/c_metrics_library.cc b/metrics/c_metrics_library.cc
index 3e2e261..90a2d59 100644
--- a/metrics/c_metrics_library.cc
+++ b/metrics/c_metrics_library.cc
@@ -6,9 +6,10 @@
 // C wrapper to libmetrics
 //
 
+#include "metrics/c_metrics_library.h"
+
 #include <string>
 
-#include "metrics/c_metrics_library.h"
 #include "metrics/metrics_library.h"
 
 extern "C" CMetricsLibrary CMetricsLibraryNew(void) {