Consistently read |CPDF_StreamParser::m_pBuf| values as uint8_t.

Since the values are stored as uint8_t in |m_pBuf| and mostly used with
functions that take uint8_t, it does not make sense to read from
|m_pBuf| into a local variable of type int.

Change-Id: Ibd1b90fa37638ddc99c0f7c2c54c890130350769
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/64992
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fpdfapi/page/cpdf_streamparser.cpp b/core/fpdfapi/page/cpdf_streamparser.cpp
index 6b486eb..6d16458 100644
--- a/core/fpdfapi/page/cpdf_streamparser.cpp
+++ b/core/fpdfapi/page/cpdf_streamparser.cpp
@@ -217,7 +217,7 @@
   if (!PositionIsInBounds())
     return EndOfData;
 
-  int ch = m_pBuf[m_Pos++];
+  uint8_t ch = m_pBuf[m_Pos++];
   while (1) {
     while (PDFCharIsWhitespace(ch)) {
       if (!PositionIsInBounds())
@@ -377,7 +377,7 @@
   if (!PositionIsInBounds())
     return;
 
-  int ch = m_pBuf[m_Pos++];
+  uint8_t ch = m_pBuf[m_Pos++];
   while (1) {
     while (PDFCharIsWhitespace(ch)) {
       if (!PositionIsInBounds()) {
@@ -561,8 +561,7 @@
   bool bFirst = true;
   int code = 0;
   while (PositionIsInBounds()) {
-    int ch = m_pBuf[m_Pos++];
-
+    uint8_t ch = m_pBuf[m_Pos++];
     if (ch == '>')
       break;