Rename impl by EncodeImpl

Change-Id: Id182cd234c9f4f37c2854ea5ca761d8cfa113791
diff --git a/vp9/simple_encode.cc b/vp9/simple_encode.cc
index c61db7c..86947b4 100644
--- a/vp9/simple_encode.cc
+++ b/vp9/simple_encode.cc
@@ -45,7 +45,7 @@
   return 1;
 }
 
-class SimpleEncode::impl {
+class SimpleEncode::EncodeImpl {
  public:
   VP9_COMP *cpi;
   vpx_img_fmt_t img_fmt;
@@ -106,7 +106,7 @@
                            int frame_rate_num, int frame_rate_den,
                            int target_bitrate, int num_frames,
                            const char *infile_path) {
-  this->impl_ptr = std::unique_ptr<impl>(new impl());
+  this->impl_ptr = std::unique_ptr<EncodeImpl>(new EncodeImpl());
   this->frame_width = frame_width;
   this->frame_height = frame_height;
   this->frame_rate_num = frame_rate_num;
diff --git a/vp9/simple_encode.h b/vp9/simple_encode.h
index 3b62d48..39b1c5e 100644
--- a/vp9/simple_encode.h
+++ b/vp9/simple_encode.h
@@ -75,7 +75,7 @@
   int GetCodingFrameNum();
 
  private:
-  class impl;
+  class EncodeImpl;
   int frame_width;
   int frame_height;
   int frame_rate_num;
@@ -83,7 +83,7 @@
   int target_bitrate;
   int num_frames;
   std::FILE *file;
-  std::unique_ptr<impl> impl_ptr;
+  std::unique_ptr<EncodeImpl> impl_ptr;
 };
 
 }  // namespace vp9