Stop using LOG macros in favor of RTC_ prefixed macros.

This CL has been generated with the following script:

for m in PLOG \
  LOG_TAG \
  LOG_GLEM \
  LOG_GLE_EX \
  LOG_GLE \
  LAST_SYSTEM_ERROR \
  LOG_ERRNO_EX \
  LOG_ERRNO \
  LOG_ERR_EX \
  LOG_ERR \
  LOG_V \
  LOG_F \
  LOG_T_F \
  LOG_E \
  LOG_T \
  LOG_CHECK_LEVEL_V \
  LOG_CHECK_LEVEL \
  LOG
do
  git grep -l $m | xargs sed -i "s,\b$m\b,RTC_$m,g"
done
git checkout rtc_base/logging.h
git cl format

Bug: webrtc:8452
Change-Id: I1a53ef3e0a5ef6e244e62b2e012b864914784600
Reviewed-on: https://webrtc-review.googlesource.com/21325
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20617}
diff --git a/rtc_base/unixfilesystem.cc b/rtc_base/unixfilesystem.cc
index 8355141..8732d47 100644
--- a/rtc_base/unixfilesystem.cc
+++ b/rtc_base/unixfilesystem.cc
@@ -58,7 +58,7 @@
 UnixFilesystem::~UnixFilesystem() {}
 
 bool UnixFilesystem::DeleteFile(const Pathname &filename) {
-  LOG(LS_INFO) << "Deleting file:" << filename.pathname();
+  RTC_LOG(LS_INFO) << "Deleting file:" << filename.pathname();
 
   if (!IsFile(filename)) {
     RTC_DCHECK(IsFile(filename));
@@ -89,8 +89,8 @@
     RTC_DCHECK(IsFile(old_path));
     return false;
   }
-  LOG(LS_VERBOSE) << "Moving " << old_path.pathname()
-                  << " to " << new_path.pathname();
+  RTC_LOG(LS_VERBOSE) << "Moving " << old_path.pathname() << " to "
+                      << new_path.pathname();
   if (rename(old_path.pathname().c_str(), new_path.pathname().c_str()) != 0) {
     return false;
   }