Fix multiline behaviors for RTL text.

- Usually, logical first segment should appear in the first line
  when multi-lined. This is the reported bug as crbug.com/458219
  Therefore, TextRunHarfBuzz should be added to the line breaker
  in the logical order.
- The segment order in a line is assumed as visual order,
  therefore it needs to be sorted.
- Modified the test expectations which support this behavior.
- Added new test cases to verify where exactly the segment is
  drawn.

BUG=458219
R=msw@chromium.org, ckocagil@chromium.org
TEST=gfx_unittests

Review URL: https://codereview.chromium.org/924773002

Cr-Commit-Position: refs/heads/master@{#316954}

1 files changed, 7 insertions, 7 deletions

diff --git a/ui/gfx/render_text.h b/ui/gfx/render_text.h
index 5a18253..2be04ac 100644
--- a/ui/gfx/render_text.h
+++ b/ui/gfx/render_text.h
@@ -45,10 +45,10 @@ class RenderTextTest;
 namespace internal {
 
 // Internal helper class used by derived classes to draw text through Skia.
-class SkiaTextRenderer {
+class GFX_EXPORT SkiaTextRenderer {
  public:
   explicit SkiaTextRenderer(Canvas* canvas);
-  ~SkiaTextRenderer();
+  virtual ~SkiaTextRenderer();
 
   void SetDrawLooper(SkDrawLooper* draw_looper);
   void SetFontRenderParams(const FontRenderParams& params,
@@ -63,14 +63,14 @@ class SkiaTextRenderer {
   // two metrics must be set together.
   void SetUnderlineMetrics(SkScalar thickness, SkScalar position);
   void DrawSelection(const std::vector<Rect>& selection, SkColor color);
-  void DrawPosText(const SkPoint* pos,
-                   const uint16* glyphs,
-                   size_t glyph_count);
+  virtual void DrawPosText(const SkPoint* pos,
+                           const uint16* glyphs,
+                           size_t glyph_count);
   // Draw underline and strike-through text decorations.
   // Based on |SkCanvas::DrawTextDecorations()| and constants from:
   //   third_party/skia/src/core/SkTextFormatParams.h
-  void DrawDecorations(int x, int y, int width, bool underline, bool strike,
-                       bool diagonal_strike);
+  virtual void DrawDecorations(int x, int y, int width, bool underline,
+                               bool strike, bool diagonal_strike);
   // Finishes any ongoing diagonal strike run.
   void EndDiagonalStrike();
   void DrawUnderline(int x, int y, int width);