logd: replace stats.add+stats.subtract with stats.addTotal

Replace stats.add(elem) + stats.subtract(elem) with a new more
efficient method stats.addTotal(elem).

Test: gTest liblog-unit-test, logd-unit-tests and logcat-unit-tests
Bug: 37254265
Change-Id: I2b3c2ac44209772b38f383ae46fe6c4422b542cf
diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index d3167ad..b41aca5 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <fcntl.h>
+#include <inttypes.h>
 #include <pwd.h>
 #include <stdio.h>
 #include <string.h>
@@ -70,20 +71,30 @@
 }
 }
 
+void LogStatistics::addTotal(LogBufferElement* element) {
+    if (element->getDropped()) return;
+
+    log_id_t log_id = element->getLogId();
+    unsigned short size = element->getMsgLen();
+    mSizesTotal[log_id] += size;
+    SizesTotal += size;
+    ++mElementsTotal[log_id];
+}
+
 void LogStatistics::add(LogBufferElement* element) {
     log_id_t log_id = element->getLogId();
     unsigned short size = element->getMsgLen();
     mSizes[log_id] += size;
     ++mElements[log_id];
 
+    // When caller adding a chatty entry, they will have already
+    // called add() and subtract() for each entry as they are
+    // evaluated and trimmed, thus recording size and number of
+    // elements, but we must recognize the manufactured dropped
+    // entry as not contributing to the lifetime totals.
     if (element->getDropped()) {
         ++mDroppedElements[log_id];
     } else {
-        // When caller adding a chatty entry, they will have already
-        // called add() and subtract() for each entry as they are
-        // evaluated and trimmed, thus recording size and number of
-        // elements, but we must recognize the manufactured dropped
-        // entry as not contributing to the lifetime totals.
         mSizesTotal[log_id] += size;
         SizesTotal += size;
         ++mElementsTotal[log_id];