Remove manual byte counting from Highlighter code.

Summary:
This removes the manual byte counting mechanism from the syntax highlighting
code. This is no longer necessary as the Stream class now has built-in support for
automatically counting the bytes that were written to it so far.

The advantage of automatic byte counting via Stream is that it is less error-prone
than the manual version and we need to write less boilerplate code.

Reviewers: labath

Reviewed By: labath

Subscribers: labath, lldb-commits

Differential Revision: https://reviews.llvm.org/D50676

llvm-svn: 339695
diff --git a/lldb/source/Core/Highlighter.cpp b/lldb/source/Core/Highlighter.cpp
index 2ef99c8..53aa16d 100644
--- a/lldb/source/Core/Highlighter.cpp
+++ b/lldb/source/Core/Highlighter.cpp
@@ -15,11 +15,8 @@
 
 using namespace lldb_private;
 
-std::size_t HighlightStyle::ColorStyle::Apply(Stream &s,
-                                              llvm::StringRef value) const {
+void HighlightStyle::ColorStyle::Apply(Stream &s, llvm::StringRef value) const {
   s << m_prefix << value << m_suffix;
-  // Calculate how many bytes we have written.
-  return m_prefix.size() + value.size() + m_suffix.size();
 }
 
 void HighlightStyle::ColorStyle::Set(llvm::StringRef prefix,
@@ -28,13 +25,11 @@
   m_suffix = lldb_utility::ansi::FormatAnsiTerminalCodes(suffix);
 }
 
-std::size_t NoHighlighter::Highlight(const HighlightStyle &options,
-                                     llvm::StringRef line,
-                                     llvm::StringRef previous_lines,
-                                     Stream &s) const {
+void NoHighlighter::Highlight(const HighlightStyle &options,
+                              llvm::StringRef line,
+                              llvm::StringRef previous_lines, Stream &s) const {
   // We just forward the input to the output and do no highlighting.
   s << line;
-  return line.size();
 }
 
 static HighlightStyle::ColorStyle GetColor(const char *c) {