Improve RenderTextWin font fallback.

Don't use SCRIPT_UNDEFINED in the case of font fallback,
unless font fallback actually fails to return a script
that can display the characters. This fixes the problem
of some scripts not being properly displayed.

This actually makes RenderTextWin properly validate whether
a text position accepts a cursor, which caused several tests
to fail and revealed some additional issues in RenderTextWin.

The CL includes some modifications to address this.

Some tests are disabled under XP, see:
http://crbug.com/106450

Also, fixes some lint warnings.

BUG=90426
TEST=Run chrome.exe --use-pure-views and paste some Bengali
text into the omnibox. It should show up properly.
Review URL: http://codereview.chromium.org/8575020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@113635 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 8 insertions, 0 deletions

diff --git a/ui/gfx/render_text.h b/ui/gfx/render_text.h
index da3607d..a812210 100644
--- a/ui/gfx/render_text.h
+++ b/ui/gfx/render_text.h
@@ -234,6 +234,9 @@ class UI_EXPORT RenderText {
   virtual void DrawVisualText(Canvas* canvas) = 0;
 
   // Get the logical index of the grapheme preceding the argument |position|.
+  // If |IsCursorablePosition(position)| is true, the result will be the start
+  // of the previous grapheme, if any. Otherwise, the result will be the start
+  // of the grapheme containing |position|.
   size_t GetIndexOfPreviousGrapheme(size_t position);
 
   // Apply composition style (underline) to composition range and selection
@@ -252,8 +255,13 @@ class UI_EXPORT RenderText {
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, CustomDefaultStyle);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, ApplyStyleRange);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, StyleRangesAdjust);
+  FRIEND_TEST_ALL_PREFIXES(RenderTextTest, GraphemePositions);
+  FRIEND_TEST_ALL_PREFIXES(RenderTextTest, SelectionModels);
 
   // Return an index belonging to the |next| or previous logical grapheme.
+  // If |next| is false and |IsCursorablePosition(index)| is true, the result
+  // will be the start of the previous grapheme, if any. Otherwise, the result
+  // will be the start of the grapheme containing |index|.
   // The return value is bounded by 0 and the text length, inclusive.
   virtual size_t IndexOfAdjacentGrapheme(size_t index, bool next) = 0;