<android/log.h>: more clarify about log ids and priorities.

Change-Id: I8745d2b18a0047192aa27d98e187ab24020495d6
diff --git a/liblog/include/android/log.h b/liblog/include/android/log.h
index 938786c..2df7fc1 100644
--- a/liblog/include/android/log.h
+++ b/liblog/include/android/log.h
@@ -94,8 +94,8 @@
 } android_LogPriority;
 
 /**
- * Writes the constant string `text` to the log, with priority `prio` and tag
- * `tag`.
+ * Writes the constant string `text` to the log,
+ * with priority `prio` (one of the `android_LogPriority` values) and tag `tag`.
  *
  * @return 1 if the message was written to the log, or -EPERM if it was not; see
  * __android_log_is_loggable().
@@ -103,7 +103,9 @@
 int __android_log_write(int prio, const char* tag, const char* text);
 
 /**
- * Writes a formatted string to the log, with priority `prio` and tag `tag`.
+ * Writes a formatted string to the log,
+ * with priority `prio` (one of the `android_LogPriority` values) and tag `tag`.
+ *
  * The details of formatting are the same as for
  * [printf(3)](http://man7.org/linux/man-pages/man3/printf.3.html).
  *
@@ -172,24 +174,25 @@
   LOG_ID_DEFAULT = 0x7FFFFFFF
 } log_id_t;
 
-static inline bool __android_log_id_is_valid(log_id_t id) {
-  return id >= LOG_ID_MIN && id < LOG_ID_MAX;
+static inline bool __android_log_id_is_valid(log_id_t log_id) {
+  return log_id >= LOG_ID_MIN && log_id < LOG_ID_MAX;
 }
 
 /**
- * Writes the constant string `text` to the log buffer `id`,
- * with priority `prio` and tag `tag`.
+ * Writes the string `text` to the log buffer `log_id` (one of the `log_id_t` values),
+ * with priority `prio` (one of the `android_LogPriority` values) and tag `tag`.
  *
  * Apps should use __android_log_write() instead.
  *
  * @return 1 if the message was written to the log, or -EPERM if it was not; see
  * __android_log_is_loggable().
  */
-int __android_log_buf_write(int bufID, int prio, const char* tag, const char* text);
+int __android_log_buf_write(int log_id, int prio, const char* tag, const char* text);
 
 /**
- * Writes a formatted string to log buffer `id`,
- * with priority `prio` and tag `tag`.
+ * Writes a formatted string to the log buffer `log_id` (one of the `log_id_t` values),
+ * with priority `prio` (one of the `android_LogPriority` values) and tag `tag`.
+ *
  * The details of formatting are the same as for
  * [printf(3)](http://man7.org/linux/man-pages/man3/printf.3.html).
  *
@@ -198,7 +201,7 @@
  * @return 1 if the message was written to the log, or -EPERM if it was not; see
  * __android_log_is_loggable().
  */
-int __android_log_buf_print(int bufID, int prio, const char* tag, const char* fmt, ...)
+int __android_log_buf_print(int log_id, int prio, const char* tag, const char* fmt, ...)
     __attribute__((__format__(printf, 4, 5)));
 
 /**
diff --git a/liblog/logger_write.cpp b/liblog/logger_write.cpp
index 99c455a..3c6ccd0 100644
--- a/liblog/logger_write.cpp
+++ b/liblog/logger_write.cpp
@@ -382,7 +382,7 @@
   logger_function(log_message);
 }
 
-int __android_log_buf_write(int bufID, int prio, const char* tag, const char* msg) {
+int __android_log_buf_write(int log_id, int prio, const char* tag, const char* msg) {
   ErrnoRestorer errno_restorer;
 
   if (!__android_log_is_loggable(prio, tag, ANDROID_LOG_VERBOSE)) {
@@ -390,7 +390,7 @@
   }
 
   __android_log_message log_message = {
-      sizeof(__android_log_message), bufID, prio, tag, nullptr, 0, msg};
+      sizeof(__android_log_message), log_id, prio, tag, nullptr, 0, msg};
   __android_log_write_log_message(&log_message);
   return 1;
 }
@@ -432,7 +432,7 @@
   return 1;
 }
 
-int __android_log_buf_print(int bufID, int prio, const char* tag, const char* fmt, ...) {
+int __android_log_buf_print(int log_id, int prio, const char* tag, const char* fmt, ...) {
   ErrnoRestorer errno_restorer;
 
   if (!__android_log_is_loggable(prio, tag, ANDROID_LOG_VERBOSE)) {
@@ -447,7 +447,7 @@
   va_end(ap);
 
   __android_log_message log_message = {
-      sizeof(__android_log_message), bufID, prio, tag, nullptr, 0, buf};
+      sizeof(__android_log_message), log_id, prio, tag, nullptr, 0, buf};
   __android_log_write_log_message(&log_message);
   return 1;
 }