Change FakeEncoder::kImplementationName from const char* to constexpr char*

Bug: b/295113672
Change-Id: I33f447c907e807bd45a4379e39fc051625afd851
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/315260
Commit-Queue: Björn Terelius <terelius@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40531}
diff --git a/test/fake_encoder.cc b/test/fake_encoder.cc
index f6a998f..1afe1f8 100644
--- a/test/fake_encoder.cc
+++ b/test/fake_encoder.cc
@@ -276,7 +276,6 @@
   }
 }
 
-const char* FakeEncoder::kImplementationName = "fake_encoder";
 VideoEncoder::EncoderInfo FakeEncoder::GetEncoderInfo() const {
   EncoderInfo info;
   MutexLock lock(&mutex_);
diff --git a/test/fake_encoder.h b/test/fake_encoder.h
index 02eeee0..b804f2c 100644
--- a/test/fake_encoder.h
+++ b/test/fake_encoder.h
@@ -65,7 +65,7 @@
   int GetNumInitializations() const RTC_LOCKS_EXCLUDED(mutex_);
   const VideoCodec& config() const RTC_LOCKS_EXCLUDED(mutex_);
 
-  static const char* kImplementationName;
+  static constexpr char kImplementationName[] = "fake_encoder";
 
  protected:
   struct FrameInfo {
diff --git a/test/fake_vp8_decoder.cc b/test/fake_vp8_decoder.cc
index 4c2f55a..137614a 100644
--- a/test/fake_vp8_decoder.cc
+++ b/test/fake_vp8_decoder.cc
@@ -77,7 +77,6 @@
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
-const char* FakeVp8Decoder::kImplementationName = "fake_vp8_decoder";
 VideoDecoder::DecoderInfo FakeVp8Decoder::GetDecoderInfo() const {
   DecoderInfo info;
   info.implementation_name = kImplementationName;
diff --git a/test/fake_vp8_decoder.h b/test/fake_vp8_decoder.h
index 391ee37..a73922e 100644
--- a/test/fake_vp8_decoder.h
+++ b/test/fake_vp8_decoder.h
@@ -38,7 +38,8 @@
 
   DecoderInfo GetDecoderInfo() const override;
   const char* ImplementationName() const override;
-  static const char* kImplementationName;
+
+  static constexpr char kImplementationName[] = "fake_vp8_decoder";
 
  private:
   DecodedImageCallback* callback_;