Factor code to rotate a canvas about a point.

samplecode/SampleFontScalerTest.cpp

Index: samplecode/SampleFontScalerTest.cpp
diff --git a/samplecode/SampleFontScalerTest.cpp b/samplecode/SampleFontScalerTest.cpp
index bd9309790e3be851a8c62d63439c6dcc470f2c1e..6198df5a1d69a75eb44ae23083a412a671b131af 100644
--- a/samplecode/SampleFontScalerTest.cpp
+++ b/samplecode/SampleFontScalerTest.cpp
@@ -19,6 +19,7 @@
 #include "SkColorPriv.h"
 #include "SkColorFilter.h"
 #include "SkDither.h"
+#include "sk_tool_utils.h"
 
 static const struct {
     const char* fName;
@@ -44,7 +45,6 @@ public:
             fFaces[i] = SkTypeface::MakeFromName(
                 gFaces[i].fName, SkFontStyle::FromOldStyle(gFaces[i].fStyle));
         }
-//        this->setBGColor(0xFFDDDDDD);
     }
 
 protected:
@@ -57,12 +57,6 @@ protected:
         return this->INHERITED::onQuery(evt);
     }
 
-    static void rotate_about(SkCanvas* canvas, SkScalar degrees, SkScalar px, SkScalar py) {
-        canvas->translate(px, py);
-        canvas->rotate(degrees);
-        canvas->translate(-px, -py);
-    }
-
     virtual void onDrawContent(SkCanvas* canvas) {
         SkPaint paint;
 
@@ -100,7 +94,7 @@ protected:
                 SkAutoCanvasRestore acr(canvas, true);
                 canvas->translate(SkIntToScalar(50 + i * 230),
                                   SkIntToScalar(20));
-                rotate_about(canvas, SkIntToScalar(i * 5), x, y * 10);
+                sk_tool_utils::rotate_about(canvas, SkIntToScalar(i * 5), x, y * 10);
 
                 {
                     SkPaint p;