metricsd: move timer.h into include/metrics/

Move timer.h into the include/metrics/ folder since some
source files in shill need to include this header file.
Adjust the timer.h include paths in the metricsd accordingly.

BUG: None
Change-Id: Id2f5e079d3a095f40d0f4d4e0d438bd22f1274ff
TEST: "mma" in metricsd folder succeeds.
diff --git a/Android.mk b/Android.mk
index c219ab1..8a0a8b4 100644
--- a/Android.mk
+++ b/Android.mk
@@ -23,7 +23,8 @@
   c_metrics_library.cc \
   metrics_library.cc \
   serialization/metric_sample.cc \
-  serialization/serialization_utils.cc
+  serialization/serialization_utils.cc \
+  timer.cc
 
 metrics_client_sources := \
   metrics_client.cc
diff --git a/timer.h b/include/metrics/timer.h
similarity index 100%
rename from timer.h
rename to include/metrics/timer.h
diff --git a/timer.cc b/timer.cc
index 7b00cc0..0c2c119 100644
--- a/timer.cc
+++ b/timer.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "timer.h"
+#include "metrics/timer.h"
 
 #include <string>
 
diff --git a/timer_mock.h b/timer_mock.h
index 8c9e8d8..200ee9a 100644
--- a/timer_mock.h
+++ b/timer_mock.h
@@ -21,7 +21,7 @@
 
 #include <gmock/gmock.h>
 
-#include "timer.h"
+#include "metrics/timer.h"
 
 namespace chromeos_metrics {
 
diff --git a/timer_test.cc b/timer_test.cc
index ab027d4..432c3d2 100644
--- a/timer_test.cc
+++ b/timer_test.cc
@@ -20,8 +20,8 @@
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
+#include "metrics/timer.h"
 #include "metrics_library_mock.h"
-#include "timer.h"
 #include "timer_mock.h"
 
 using ::testing::_;