Implement right-to-left text rendering in Pepper.

TEST=included
BUG=http://crbug.com/134394

Review URL: https://chromiumcodereview.appspot.com/10658037

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@144623 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 17 insertions, 1 deletions

diff --git a/ppapi/api/dev/ppb_font_dev.idl b/ppapi/api/dev/ppb_font_dev.idl
index f951d8d..5d582d1 100644
--- a/ppapi/api/dev/ppb_font_dev.idl
+++ b/ppapi/api/dev/ppb_font_dev.idl
@@ -122,12 +122,28 @@ struct PP_TextRun_Dev {
 
   /**
    * Set to PP_TRUE if the text is right-to-left.
+   *
+   * When <code>override_direction</code> is false, the browser will perform
+   * the Unicode Bidirectional Algorithm (http://unicode.org/reports/tr9/) on
+   * the text. The value of the <code>rtl</code> flag specifies the
+   * direcionality of the surrounding environment. This means that Hebrew
+   * word will always display right to left, even if <code>rtl</code> is false.
+   *
+   * When <code>override_direction</code> is true, no autodetection will be done
+   * and <code>rtl</code> specifies the direction of the text.
+   *
+   * TODO(brettw) note that autodetection with rtl = true is currently
+   * unimplemented.
    */
   PP_Bool rtl;
 
   /**
    * Set to PP_TRUE to force the directionality of the text regardless of
-   * content
+   * content.
+   *
+   * If this flag is set, the browser will skip autodetection of the content
+   * and will display all text in the direction speficied by the
+   * <code>rtl</code> flag.
    */
   PP_Bool override_direction;
 };