gdb/tui: make m_horizontal_offset private

I noticed that tui_source_window_base::m_horizontal_offset was
protected, but could be made private, so lets do that.

This makes more sense in the context of a later commit where I plan to
add another member variable that is similar to m_horizontal_offset.
The new member variable could also be private.

So I had to choose, place the new member variable next to
m_horizontal_offset making it protected, but grouping similar
variables together, or make m_horizontal_offset private, and then add
the new variable as private too.

I chose to make m_horizontal_offset private, which is this commit.

There should be no user visible changes after this commit.

1 files changed, 4 insertions, 2 deletions

diff --git a/gdb/tui/tui-winsource.h b/gdb/tui/tui-winsource.h
index 7d6d64d..bf0ca96 100644
--- a/gdb/tui/tui-winsource.h
+++ b/gdb/tui/tui-winsource.h
@@ -124,8 +124,7 @@ protected:
   /* Redraw the complete line of a source or disassembly window.  */
   void show_source_line (int lineno);
 
-  /* Used for horizontal scroll.  */
-  int m_horizontal_offset = 0;
+  /* Where to start generating content from.  */
   struct tui_line_or_address m_start_line_or_addr;
 
   /* Architecture associated with code at this location.  */
@@ -179,6 +178,9 @@ public:
 
 private:
 
+  /* Used for horizontal scroll.  */
+  int m_horizontal_offset = 0;
+
   void show_source_content ();
 
   /* Called when the user "set style enabled" setting is changed.  */