liblog: Add log_time += operator

Change-Id: I1d2987b6cb333fc344d4fee1b7bb25f32a4143c6
diff --git a/liblog/log_time.cpp b/liblog/log_time.cpp
index 209a9da..50742df 100644
--- a/liblog/log_time.cpp
+++ b/liblog/log_time.cpp
@@ -150,6 +150,17 @@
     return *this;
 }
 
+log_time log_time::operator+= (const timespec &T) {
+    this->tv_nsec += (unsigned long int)T.tv_nsec;
+    if (this->tv_nsec >= NS_PER_SEC) {
+        this->tv_nsec -= NS_PER_SEC;
+        ++this->tv_sec;
+    }
+    this->tv_sec += T.tv_sec;
+
+    return *this;
+}
+
 log_time log_time::operator-= (const log_time &T) {
     // No concept of negative time, clamp to EPOCH
     if (*this <= T) {
@@ -166,3 +177,14 @@
 
     return *this;
 }
+
+log_time log_time::operator+= (const log_time &T) {
+    this->tv_nsec += T.tv_nsec;
+    if (this->tv_nsec >= NS_PER_SEC) {
+        this->tv_nsec -= NS_PER_SEC;
+        ++this->tv_sec;
+    }
+    this->tv_sec += T.tv_sec;
+
+    return *this;
+}