Delete deprecated static method FileStream::GetSize.

Unused since cl https://codereview.webrtc.org/2694753002

Bug: webrtc:6424
Change-Id: Id22ecd5c004a0b4af3e673da519cbd537f99cd8b
Reviewed-on: https://chromium-review.googlesource.com/626116
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Original-Commit-Position: refs/heads/master@{#19482}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: eaea27799d7140c1b56e76562e34ab6e036b2fb5
diff --git a/rtc_base/stream.cc b/rtc_base/stream.cc
index df2d665..32b9eac 100644
--- a/rtc_base/stream.cc
+++ b/rtc_base/stream.cc
@@ -472,14 +472,6 @@
   return true;
 }
 
-bool FileStream::GetSize(const std::string& filename, size_t* size) {
-  struct stat file_stats;
-  if (stat(filename.c_str(), &file_stats) != 0)
-    return false;
-  *size = file_stats.st_size;
-  return true;
-}
-
 bool FileStream::Flush() {
   if (file_) {
     return (0 == fflush(file_));
diff --git a/rtc_base/stream.h b/rtc_base/stream.h
index 601ef66..8b7b036 100644
--- a/rtc_base/stream.h
+++ b/rtc_base/stream.h
@@ -407,9 +407,6 @@
   bool Unlock();
 #endif
 
-  // Note: Deprecated in favor of Filesystem::GetFileSize().
-  static bool GetSize(const std::string& filename, size_t* size);
-
  protected:
   virtual void DoClose();