Move allow_character_break property to RenderText.

ui/gfx/render_text_harfbuzz.cc

Index: ui/gfx/render_text_harfbuzz.cc
diff --git a/ui/gfx/render_text_harfbuzz.cc b/ui/gfx/render_text_harfbuzz.cc
index 63b0e4e0cd79d009e83cb9989e680f987def1e06..0cd2dadea630cd2f5f9b1f3d09f893497d38477d 100644
--- a/ui/gfx/render_text_harfbuzz.cc
+++ b/ui/gfx/render_text_harfbuzz.cc
@@ -223,6 +223,7 @@ class HarfBuzzLineBreaker {
                       int min_baseline,
                       float min_height,
                       bool multiline,
+                      bool allow_character_break,
                       const base::string16& text,
                       const BreakList<size_t>* words,
                       const internal::TextRunList& run_list)
@@ -230,6 +231,7 @@ class HarfBuzzLineBreaker {
         min_baseline_(min_baseline),
         min_height_(min_height),
         multiline_(multiline),
+        allow_character_break_(allow_character_break),
         text_(text),
         words_(words),
         run_list_(run_list),
@@ -335,7 +337,7 @@ class HarfBuzzLineBreaker {
       word_width += char_width;
 
       if (*width > available_width) {
-        if (line_x_ != 0 || word_width < *width) {
+        if (!allow_character_break_ && (line_x_ != 0 || word_width < *width)) {

[msw, 2015/03/25 20:54:15]

I don't think this matches the current Label behavior of toggling between
gfx::WRAP_LONG_WORDS and gfx::TRUNCATE_LONG_WORDS...

Afaict, this is the expected behavior, can you confirm?
1) TRUNCATE_LONG_WORDS (allow_character_break_ == false): Move long words to a
new line (if there is preceding text on the current line), then *truncate any
word content beyond the width of a full line*.
2) WRAP_LONG_WORDS (allow_character_break_ == true): Move long words to a new
line (if there is preceding text on the current line), then *continually wrap
the word content as needed onto subsequent lines.*
3) RenderText ToT: Matches WRAP_LONG_WORDS (allow_character_break_ == true)?
4) With this change: *Never move long words onto new lines* (WRONG), just
continually wrap the word content as needed...

We should clarify the gfx::WordWrapBehavior enums comments and add more testing.

[Jun Mukai, 2015/03/26 01:35:08]

Rewritten the logic, and enriched the tests. PTAL.

           // Roll back one word.
           *width -= word_width;
           *next_char = std::max(word->first, start_char);
@@ -444,6 +446,7 @@ class HarfBuzzLineBreaker {
   const int min_baseline_;
   const float min_height_;
   const bool multiline_;
+  const bool allow_character_break_;
   const base::string16& text_;
   const BreakList<size_t>* const words_;
   const internal::TextRunList& run_list_;
@@ -986,7 +989,8 @@ void RenderTextHarfBuzz::EnsureLayout() {
     HarfBuzzLineBreaker line_breaker(
         display_rect().width(), font_list().GetBaseline(),
         std::max(font_list().GetHeight(), min_line_height()), multiline(),
-        GetDisplayText(), multiline() ? &GetLineBreaks() : nullptr, *run_list);
+        allow_character_break(), GetDisplayText(),
+        multiline() ? &GetLineBreaks() : nullptr, *run_list);
 
     // TODO(vadimt): Remove ScopedTracker below once crbug.com/431326 is fixed.
     tracked_objects::ScopedTracker tracking_profile3(