video_source.h: Minor clean up.

- Use size_t for frame_size() (fixes warnings elsewhere)
- Remove unnecessary use of const.

Change-Id: Id2cba182ac3fd2f67d25fd1db3a0bc3e1eda040b

test/ivf_video_source.h

@@ -94,14 +94,14 @@ class IVFVideoSource : public CompressedVideoSource {
   virtual const uint8_t *cxdata() const {
     return end_of_file_ ? NULL : compressed_frame_buf_;
   }
-  virtual const unsigned int frame_size() const { return frame_sz_; }
-  virtual const unsigned int frame_number() const { return frame_; }
+  virtual size_t frame_size() const { return frame_sz_; }
+  virtual unsigned int frame_number() const { return frame_; }
 
  protected:
   std::string file_name_;
   FILE *input_file_;
   uint8_t *compressed_frame_buf_;
-  unsigned int frame_sz_;
+  size_t frame_sz_;
   unsigned int frame_;
   bool end_of_file_;
 };

test/video_source.h

@@ -184,9 +184,9 @@ class CompressedVideoSource {
 
   virtual const uint8_t *cxdata() const = 0;
 
-  virtual const unsigned int frame_size() const = 0;
+  virtual size_t frame_size() const = 0;
 
-  virtual const unsigned int frame_number() const = 0;
+  virtual unsigned int frame_number() const = 0;
 };
 
 }  // namespace libvpx_test

test/webm_video_source.h

@@ -169,8 +169,8 @@ class WebMVideoSource : public CompressedVideoSource {
   virtual const uint8_t *cxdata() const {
     return end_of_file_ ? NULL : buf_;
   }
-  virtual const unsigned int frame_size() const { return buf_sz_; }
-  virtual const unsigned int frame_number() const { return frame_; }
+  virtual size_t frame_size() const { return buf_sz_; }
+  virtual unsigned int frame_number() const { return frame_; }
 
  protected:
   std::string file_name_;