Add Jpeg frame writer for test support.

webrtc/test/testsupport/test_output.cc

Index: webrtc/test/testsupport/test_output.cc
diff --git a/webrtc/test/testsupport/test_output.cc b/webrtc/test/testsupport/test_output.cc
index aea5110d97d13d8915508702d61046fca73c1497..281324ef138634b488d302a20c837779e93e8600 100644
--- a/webrtc/test/testsupport/test_output.cc
+++ b/webrtc/test/testsupport/test_output.cc
@@ -12,32 +12,33 @@
 
 #include <string.h>
 
-#include "gflags/gflags.h"
+#include "webrtc/rtc_base/flags.h"
 #include "webrtc/rtc_base/file.h"
 #include "webrtc/rtc_base/logging.h"
 #include "webrtc/rtc_base/pathutils.h"
 #include "webrtc/test/testsupport/fileutils.h"
 
+// Have to be strdup because |DEFINE_string| macro defines |char*|.
 DEFINE_string(test_output_dir,
-              webrtc::test::OutputPath(),
+              strdup(webrtc::test::OutputPath().c_str()),

[pbos-webrtc, 2017/07/26 18:48:03]

I think this should be a const std::string kDefaultOutputPath =
webrtc::test::OutputPath(); then, this strdup leaks.

Use kDefaultOutputPath.c_str() as a default value then.

[ilnik, 2017/08/17 11:35:07]

Done.

               "The output folder where test output should be saved.");
 
 namespace webrtc {
 namespace test {
 
 bool GetTestOutputDir(std::string* out_dir) {
-  if (FLAGS_test_output_dir.empty()) {
+  if (FLAG_test_output_dir == nullptr || strlen(FLAG_test_output_dir) == 0) {

[pbos-webrtc, 2017/07/26 18:48:03]

Can this be if (std::string(FLAG_test_output_dir) != "", or
strcmp(FLAG_test_output_dir, "") == 0)?

This should never be nullptr, right?

[ilnik, 2017/08/17 11:35:07]

Yes, it can't be nullptr ever. Still, I think strlen fits here better.

     LOG(LS_WARNING) << "No test_out_dir defined.";
     return false;
   }
-  *out_dir = FLAGS_test_output_dir;
+  *out_dir = FLAG_test_output_dir;
   return true;
 }
 
 bool WriteToTestOutput(const char* filename,
                        const uint8_t* buffer,
                        size_t length) {
-  if (FLAGS_test_output_dir.empty()) {
+  if (FLAG_test_output_dir == nullptr || strlen(FLAG_test_output_dir) == 0) {

[pbos-webrtc, 2017/07/26 18:48:03]

ditto

[ilnik, 2017/08/17 11:35:07]

Done.

     LOG(LS_WARNING) << "No test_out_dir defined.";
     return false;
   }
@@ -48,7 +49,7 @@ bool WriteToTestOutput(const char* filename,
   }
 
   rtc::File output =
-      rtc::File::Create(rtc::Pathname(FLAGS_test_output_dir, filename));
+      rtc::File::Create(rtc::Pathname(FLAG_test_output_dir, filename));
 
   return output.IsOpen() && output.Write(buffer, length) == length;
 }