Make CBC_PDF417HighLevelEncoder::encodeText() faster.

Call WideString::Reserve() to prevent excessive reallocation. Fix some
nits as well.

BUG=chromium:902302

Change-Id: I0c22dd7b286728f12ceca3f029c0dd555fc632f8
Reviewed-on: https://pdfium-review.googlesource.com/c/45651
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

fxbarcode/pdf417/BC_PDF417HighLevelEncoder.cpp

diff --git a/fxbarcode/pdf417/BC_PDF417HighLevelEncoder.cpp b/fxbarcode/pdf417/BC_PDF417HighLevelEncoder.cpp
index 7deca0f..e7e64e8 100644
--- a/fxbarcode/pdf417/BC_PDF417HighLevelEncoder.cpp
+++ b/fxbarcode/pdf417/BC_PDF417HighLevelEncoder.cpp
@@ -157,6 +157,7 @@
                                                WideString& sb,
                                                int32_t initialSubmode) {
   WideString tmp;
+  tmp.Reserve(count);
   int32_t submode = initialSubmode;
   size_t idx = 0;
   while (true) {
@@ -185,11 +186,10 @@
         break;
       case SUBMODE_LOWER:
         if (isAlphaLower(ch)) {
-          if (ch == ' ') {
+          if (ch == ' ')
             tmp += 26;
-          } else {
+          else
             tmp += ch - 97;
-          }
           break;
         }
         if (isAlphaUpper(ch)) {