Remove SetExecutablePath, simplify ResourcePath

SetExecutablePath isn't used anymore.

Nobody was using the fancy select-per-platform functionality, and the
documentation was wrong anyway. In the cases somebody needed an
override per platform, they were using defines in their own test
instead. I think that is more verbose but more predictable and easy
to understand (see how it's done in audio_processing_unittest.cc
when loading output_data_mac, for instance).

Bug: webrtc:9792
Change-Id: I7289bf5883fe43852638922d7c7583eae0c08601
Reviewed-on: https://webrtc-review.googlesource.com/c/104482
Commit-Queue: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25062}
diff --git a/test/testsupport/fileutils.h b/test/testsupport/fileutils.h
index 5ff0196..693944e 100644
--- a/test/testsupport/fileutils.h
+++ b/test/testsupport/fileutils.h
@@ -51,18 +51,8 @@
 std::string GenerateTempFilename(const std::string& dir,
                                  const std::string& prefix);
 
-// Returns a path to a resource file for the currently executing platform.
-// Adapts to what filenames are currently present in the
-// [project-root]/resources/ dir.
-// Returns an absolute path according to this priority list (the directory
-// part of the path is left out for readability):
-// 1. [name]_[platform]_[architecture].[extension]
-// 2. [name]_[platform].[extension]
-// 3. [name]_[architecture].[extension]
-// 4. [name].[extension]
-// Where
-// * platform is either of "win", "mac" or "linux".
-// * architecture is either of "32" or "64".
+// Returns a path to a resource file in [project-root]/resources/ dir.
+// Returns an absolute path
 //
 // Arguments:
 //    name - Name of the resource file. If a plain filename (no directory path)
@@ -110,15 +100,6 @@
 // empty or if the file does not exist/is readable.
 size_t GetFileSize(const std::string& filename);
 
-// Sets the executable path, i.e. the path to the executable that is being used
-// when launching it. This is usually the path relative to the working directory
-// but can also be an absolute path. The intention with this function is to pass
-// the argv[0] being sent into the main function to make it possible for
-// fileutils.h to find the correct project paths even when the working directory
-// is outside the project tree (which happens in some cases).
-// TODO(bugs.webrtc.org/9792): Deprecated - going away soon.
-void SetExecutablePath(const std::string& path_to_executable);
-
 }  // namespace test
 }  // namespace webrtc