Track the region where text is painted.

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

Index: Source/core/platform/graphics/chromium/UniscribeHelper.h
diff --git a/Source/core/platform/graphics/chromium/UniscribeHelper.h b/Source/core/platform/graphics/chromium/UniscribeHelper.h
index 27a30931c83509290ddaa1fd4745076c35256f9f..a74ab9020f86cd7763d2f419610d2b621c179ebd 100644
--- a/Source/core/platform/graphics/chromium/UniscribeHelper.h
+++ b/Source/core/platform/graphics/chromium/UniscribeHelper.h
@@ -44,6 +44,7 @@ class UniscribeTest_TooBig_Test; // A gunit test for UniscribeHelper.
 
 namespace WebCore {
 
+class FloatRect;
 class FontFeatureSettings;
 class GraphicsContext;
 
@@ -196,8 +197,10 @@ public:
     // be pre-set.
     //
     // The y position is the upper left corner, NOT the baseline.
-    void draw(GraphicsContext* graphicsContext, HDC dc, int x, int y, int from,
-              int to);
+    void draw(GraphicsContext* graphicsContext, HDC dc,
+              int x, int y,
+              const FloatRect& textRect,
+              int from, int to);
 
     // Returns the first glyph assigned to the character at the given offset.
     // This function is used to retrieve glyph information when Uniscribe is