Concatenate string literals at compile time.

This CL was generated by running:
git ls-files | grep ".cc" | xargs perl -i -ne 'BEGIN {undef $/}; s/("[\s\n]*<<[\s\n]*")/" "/g; print;'; git cl format

After that I manually edited modules/audio_processing/gain_controller2.cc to preserve its original
formatting.

This primary benefit of this change is a small reduction in binary size.

Bug: None
Change-Id: I689fa7ba9c717c314bb167e5d592c3c4e0871e29
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/165961
Reviewed-by: Alessio Bazzica <alessiob@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Jonas Olsson <jonasolsson@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30251}

logging/rtc_event_log/rtc_event_log_impl.cc

@@ -93,7 +93,8 @@ bool RtcEventLogImpl::StartLogging(std::unique_ptr<RtcEventLogOutput> output,
   const int64_t timestamp_us = rtc::TimeMicros();
   const int64_t utc_time_us = rtc::TimeUTCMicros();
   RTC_LOG(LS_INFO) << "Starting WebRTC event log. (Timestamp, UTC) = "
-                   << "(" << timestamp_us << ", " << utc_time_us << ").";
+                      "("
+                   << timestamp_us << ", " << utc_time_us << ").";
 
   RTC_DCHECK_RUN_ON(&logging_state_checker_);
   logging_state_started_ = true;