Move unusual character block logic to a helper function

ui/gfx/render_text_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/render_text_win.h"
 
 #include <algorithm>
 
 #include "base/i18n/break_iterator.h"
 #include "base/i18n/char_iterator.h"
@@ skipping 246 matching lines @@
     }
   }
 }
 
 // Returns true if characters of |block_code| may trigger font fallback.
 bool IsUnusualBlockCode(const UBlockCode block_code) {
   return block_code == UBLOCK_GEOMETRIC_SHAPES ||
          block_code == UBLOCK_MISCELLANEOUS_SYMBOLS;
 }
 
+// Returns the index of the first unusual character after a usual character or
+// vice versa. Unusual characters are defined by |IsUnusualBlockCode|.
+size_t FindUnusualCharacter(const base::string16& text,
+                            size_t run_start,
+                            size_t run_break) {
+  const int32 run_length = static_cast<int32>(run_break - run_start);
+  base::i18n::UTF16CharIterator iter(text.c_str() + run_start,
+                                     run_length);
+  const UBlockCode first_block_code = ublock_getCode(iter.get());
+  const bool first_block_unusual = IsUnusualBlockCode(first_block_code);
+  while (iter.Advance() && iter.array_pos() < run_length) {
+    const UBlockCode current_block_code = ublock_getCode(iter.get());
+    if (current_block_code != first_block_code &&
+        (first_block_unusual || IsUnusualBlockCode(current_block_code))) {
+      return run_start + iter.array_pos();
+    }
+  }
+  return run_break;
+}
+
 }  // namespace
 
 namespace internal {
 
 TextRun::TextRun()
   : font_style(0),
     strike(false),
     diagonal_strike(false),
     underline(false),
     width(0),
@@ skipping 671 matching lines @@
     if ((run_break - run->range.start()) > max_run_length) {
       run_break = run->range.start() + max_run_length;
       if (!IsValidCodePointIndex(layout_text, run_break))
         --run_break;
     }
 
     // Break runs adjacent to character substrings in certain code blocks.
     // This avoids using their fallback fonts for more characters than needed,
     // in cases like "\x25B6 Media Title", etc. http://crbug.com/278913
     if (run_break > run->range.start()) {
-      const size_t run_start = run->range.start();
-      const int32 run_length = static_cast<int32>(run_break - run_start);
-      base::i18n::UTF16CharIterator iter(layout_text.c_str() + run_start,
-                                         run_length);
-      const UBlockCode first_block_code = ublock_getCode(iter.get());
-      const bool first_block_unusual = IsUnusualBlockCode(first_block_code);
-      while (iter.Advance() && iter.array_pos() < run_length) {
-        const UBlockCode current_block_code = ublock_getCode(iter.get());
-        if (current_block_code != first_block_code &&
-            (first_block_unusual || IsUnusualBlockCode(current_block_code))) {
-          run_break = run_start + iter.array_pos();
-          break;
-        }
-      }
+      run_break =
+          FindUnusualCharacter(layout_text, run->range.start(), run_break);
     }
 
     DCHECK(IsValidCodePointIndex(layout_text, run_break));
 
     style.UpdatePosition(LayoutIndexToTextIndex(run_break));
     if (script_item_break == run_break)
       script_item++;
     run->range.set_end(run_break);
     runs_.push_back(run);
   }
@@ skipping 290 matching lines @@
   size_t position = LayoutIndexToTextIndex(run->range.end());
   position = IndexOfAdjacentGrapheme(position, CURSOR_BACKWARD);
   return SelectionModel(position, CURSOR_FORWARD);
 }
 
 RenderText* RenderText::CreateNativeInstance() {
   return new RenderTextWin;
 }
 
 }  // namespace gfx