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}

rtc_base/logging_unittest.cc

@@ -339,8 +339,10 @@ TEST(LogTest, Perf) {
   stream.Close();
 
   EXPECT_EQ(str.size(), (message.size() + logging_overhead) * kRepetitions);
-  RTC_LOG(LS_INFO) << "Total log time: " << TimeDiff(finish, start) << " ms "
-                   << " total bytes logged: " << str.size();
+  RTC_LOG(LS_INFO) << "Total log time: " << TimeDiff(finish, start)
+                   << " ms "
+                      " total bytes logged: "
+                   << str.size();
 }
 
 TEST(LogTest, EnumsAreSupported) {