Remove the monotonic option for logging

This has been around for ~5 years but there has been roughly no
adoption, so remove this as we clean up the logging code.

Future efforts may track the monotonic timestamp in all cases.

Test: logging unit tests
Change-Id: I55ed565669f923988e741f6b384141bba893630d
diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index a7323e8..2cb0c5e 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -50,48 +50,6 @@
             setSize(i, LOG_BUFFER_MIN_SIZE);
         }
     }
-    bool lastMonotonic = monotonic;
-    monotonic = android_log_clockid() == CLOCK_MONOTONIC;
-    if (lastMonotonic != monotonic) {
-        //
-        // Fixup all timestamps, may not be 100% accurate, but better than
-        // throwing what we have away when we get 'surprised' by a change.
-        // In-place element fixup so no need to check reader-lock. Entries
-        // should already be in timestamp order, but we could end up with a
-        // few out-of-order entries if new monotonics come in before we
-        // are notified of the reinit change in status. A Typical example would
-        // be:
-        //  --------- beginning of system
-        //      10.494082   184   201 D Cryptfs : Just triggered post_fs_data
-        //  --------- beginning of kernel
-        //       0.000000     0     0 I         : Initializing cgroup subsys
-        // as the act of mounting /data would trigger persist.logd.timestamp to
-        // be corrected. 1/30 corner case YMMV.
-        //
-        rdlock();
-        LogBufferElementCollection::iterator it = mLogElements.begin();
-        while ((it != mLogElements.end())) {
-            LogBufferElement* e = *it;
-            if (monotonic) {
-                if (!android::isMonotonic(e->mRealTime)) {
-                    LogKlog::convertRealToMonotonic(e->mRealTime);
-                    if ((e->mRealTime.tv_nsec % 1000) == 0) {
-                        e->mRealTime.tv_nsec++;
-                    }
-                }
-            } else {
-                if (android::isMonotonic(e->mRealTime)) {
-                    LogKlog::convertMonotonicToReal(e->mRealTime);
-                    if ((e->mRealTime.tv_nsec % 1000) == 0) {
-                        e->mRealTime.tv_nsec++;
-                    }
-                }
-            }
-            ++it;
-        }
-        unlock();
-    }
-
     // Release any sleeping reader threads to dump their current content.
     LogReaderThread::wrlock();
 
@@ -106,10 +64,7 @@
 }
 
 LogBuffer::LogBuffer(LastLogTimes* times, LogTags* tags, PruneList* prune)
-    : monotonic(android_log_clockid() == CLOCK_MONOTONIC),
-      mTimes(*times),
-      tags_(tags),
-      prune_(prune) {
+    : mTimes(*times), tags_(tags), prune_(prune) {
     pthread_rwlock_init(&mLogElementsLock, nullptr);
 
     log_id_for_each(i) {