Revert of Combine 'pssh' parsing routines.

media/formats/mp4/box_reader.h

Index: media/formats/mp4/box_reader.h
diff --git a/media/formats/mp4/box_reader.h b/media/formats/mp4/box_reader.h
index 92e85fc44fade4ce118914b1f47d1d363decf549..6b59361612459d84e29448c3b19b43595ab98cce 100644
--- a/media/formats/mp4/box_reader.h
+++ b/media/formats/mp4/box_reader.h
@@ -101,14 +101,6 @@
                                int* box_size,
                                bool* err) WARN_UNUSED_RESULT;
 
-  // Create a BoxReader from a buffer. |buf| must be the complete buffer, as
-  // errors are returned when sufficient data is not available. |buf| can start
-  // with any type of box -- it does not have to be IsValidTopLevelBox().
-  //
-  // |buf| is retained but not owned, and must outlive the BoxReader instance.
-  static BoxReader* ReadConcatentatedBoxes(const uint8* buf,
-                                           const int buf_size);
-
   // Returns true if |type| is recognized to be a top-level box, false
   // otherwise. This returns true for some boxes which we do not parse.
   // Helpful in debugging misaligned appends.
@@ -156,9 +148,7 @@
   const LogCB& log_cb() const { return log_cb_; }
 
  private:
-  // Create a BoxReader from |buf|. |is_EOS| should be true if |buf| is
-  // complete stream (i.e. no additional data is expected to be appended).
-  BoxReader(const uint8* buf, const int size, const LogCB& log_cb, bool is_EOS);
+  BoxReader(const uint8* buf, const int size, const LogCB& log_cb);
 
   // Must be called immediately after init. If the return is false, this
   // indicates that the box header and its contents were not available in the
@@ -180,9 +170,6 @@
   // valid if scanned_ is true.
   ChildMap children_;
   bool scanned_;
-
-  // True if the buffer provided to the reader is the complete stream.
-  const bool is_EOS_;
 };
 
 // Template definitions
@@ -220,8 +207,8 @@
   scanned_ = true;
 
   bool err = false;
-  while (pos_ < size_) {
-    BoxReader child_reader(&buf_[pos_], size_ - pos_, log_cb_, is_EOS_);
+  while (pos() < size()) {
+    BoxReader child_reader(&buf_[pos_], size_ - pos_, log_cb_);
     if (!child_reader.ReadHeader(&err)) break;
     T child;
     RCHECK(child.Parse(&child_reader));