Cleanup usages of Mid(foo, 1), Right(1), and Left(1)chromium/3203

Mid(foo, 1) is equivalent to [foo], if all you want is the character. Similarly
Left(1) is [0]. It is faster also, since it does not need to create intermediate
strings.

Right(1) is a touch more tricky, since it requires something like GetLength() ?
[GetLength() - 1] : 0;. A new method, Last() has been added to perform this
character extraction.

Multiple call sites have been updated to use more efficient/simpler
syntax. There are a number of call sites that use on these patterns, but based
on the surrounding context we actually need/want a string, so they have not been
modified.

Change-Id: I485a7f9c7b34c9bdacecada610158f996816afdd
Reviewed-on: https://pdfium-review.googlesource.com/12890
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp b/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
index b02efbb45d..b80100a5f0 100644
--- a/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
+++ b/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
@@ -170,7 +170,7 @@ CXFA_Node* ResolveBreakTarget(CXFA_Node* pPageSetRoot,
         return pNode;
     } else if (bNewExprStyle) {
       CFX_WideString wsProcessedTarget = wsExpr;
-      if (wsExpr.Left(4) == L"som(" && wsExpr.Right(1) == L")") {
+      if (wsExpr.Left(4) == L"som(" && wsExpr.Last() == L')') {
         wsProcessedTarget = wsExpr.Mid(4, wsExpr.GetLength() - 5);
       }
       XFA_RESOLVENODE_RS rs;