Reformat the WebRTC code base

Running clang-format with chromium's style guide.

The goal is n-fold:
 * providing consistency and readability (that's what code guidelines are for)
 * preventing noise with presubmit checks and git cl format
 * building on the previous point: making it easier to automatically fix format issues
 * you name it

Please consider using git-hyper-blame to ignore this commit.

Bug: webrtc:9340
Change-Id: I694567c4cdf8cee2860958cfe82bfaf25848bb87
Reviewed-on: https://webrtc-review.googlesource.com/81185
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23660}

test/testsupport/fileutils.h

@@ -41,7 +41,7 @@ std::string OutputPath();
 // Generates an empty file with a unique name in the specified directory and
 // returns the file name and path.
 // TODO(titovartem) rename to TempFile and next method to TempFilename
-std::string TempFilename(const std::string &dir, const std::string &prefix);
+std::string TempFilename(const std::string& dir, const std::string& prefix);
 
 // Generates a unique file name that can be used for file creation. Doesn't
 // create any files.