[AiS] for desktop, two lines and font sytles

ui/gfx/render_text.cc

Index: ui/gfx/render_text.cc
diff --git a/ui/gfx/render_text.cc b/ui/gfx/render_text.cc
index c9fe334e585135a77199c41d03c0b6bb3efcb1f7..589a9c7b631bb4a23811307895990d3b01dc3157 100644
--- a/ui/gfx/render_text.cc
+++ b/ui/gfx/render_text.cc
@@ -445,21 +445,17 @@ void RenderText::SetText(const base::string16& text) {
   DCHECK(!composition_range_.IsValid());
   if (text_ == text)
     return;
-  text_ = text;
+  text_.clear();
+  AppendText(text);
 
-  // Adjust ranged styles, baselines, and colors to accommodate a new text
-  // length. Clear style ranges as they might break new text graphemes and apply
+  // Clear style ranges as they might break new text graphemes and apply
   // the first style to the whole text instead.
-  const size_t text_length = text_.length();
-  colors_.SetMax(text_length);
+  colors_.SetValue(colors_.breaks().begin()->second);
   baselines_.SetValue(baselines_.breaks().begin()->second);
-  baselines_.SetMax(text_length);
   for (size_t style = 0; style < NUM_TEXT_STYLES; ++style) {
     BreakList<bool>& break_list = styles_[style];
     break_list.SetValue(break_list.breaks().begin()->second);
-    break_list.SetMax(text_length);
   }
-  cached_bounds_and_offset_valid_ = false;
 
   // Reset selection model. SetText should always followed by SetSelectionModel
   // or SetCursorPosition in upper layer.
@@ -468,7 +464,19 @@ void RenderText::SetText(const base::string16& text) {
   // Invalidate the cached text direction if it depends on the text contents.
   if (directionality_mode_ == DIRECTIONALITY_FROM_TEXT)
     text_direction_ = base::i18n::UNKNOWN_DIRECTION;
+}
 
+void RenderText::AppendText(const base::string16& text) {
+  text_ += text;
+  // Adjust ranged styles and colors to accommodate a new text length.
+  const size_t text_length = text_.length();
+  colors_.SetMax(text_length);
+  baselines_.SetMax(text_length);
+  for (size_t style = 0; style < NUM_TEXT_STYLES; ++style) {
+    BreakList<bool>& break_list = styles_[style];
+    break_list.SetMax(text_length);
+  }
+  cached_bounds_and_offset_valid_ = false;
   obscured_reveal_index_ = -1;
   OnTextAttributeChanged();
 }