Track the region where text is painted.

Source/core/platform/graphics/chromium/UniscribeHelper.cpp

Index: Source/core/platform/graphics/chromium/UniscribeHelper.cpp
diff --git a/Source/core/platform/graphics/chromium/UniscribeHelper.cpp b/Source/core/platform/graphics/chromium/UniscribeHelper.cpp
index 83ee2408a3e710712253e89245474af2024f5f35..20dd4a26bff12b15bbd6dfeaeafe799ac3c679d4 100644
--- a/Source/core/platform/graphics/chromium/UniscribeHelper.cpp
+++ b/Source/core/platform/graphics/chromium/UniscribeHelper.cpp
@@ -324,8 +324,10 @@ int UniscribeHelper::xToCharacter(int x) const
     return 0;
 }
 
-void UniscribeHelper::draw(GraphicsContext* graphicsContext,
-                           HDC dc, int x, int y, int from, int to)
+void UniscribeHelper::draw(GraphicsContext* graphicsContext, HDC dc,
+                           int x, int y,
+                           const FloatRect& textRect,
+                           int from, int to)
 {
     HGDIOBJ oldFont = 0;
     int curX = x;
@@ -426,7 +428,8 @@ void UniscribeHelper::draw(GraphicsContext* graphicsContext,
                               &shaping.m_glyphs[fromGlyph],
                               advances,
                               &shaping.m_offsets[fromGlyph],
-                              &origin);
+                              origin,
+                              textRect);
                 textOutOk = true;
 
                 if (!textOutOk && 0 == executions) {