Cleanup: Get rid of make_isize() function from gm.h.

gm/gradtext.cpp

Index: gm/gradtext.cpp
diff --git a/gm/gradtext.cpp b/gm/gradtext.cpp
index 42513b73dec3ba2997edcd343db406b166240592..5fac185c9d25ddb48fddfde80df2f9e835846a98 100644
--- a/gm/gradtext.cpp
+++ b/gm/gradtext.cpp
@@ -44,7 +44,7 @@ public:
 protected:
 
     virtual SkString onShortName() { return SkString("chrome_gradtext1"); }
-    virtual SkISize onISize() { return make_isize(500, 480); }
+    virtual SkISize onISize() { return SkISize::Make(500, 480); }
     virtual void onDraw(SkCanvas* canvas) {
         SkPaint paint;
         SkRect r = SkRect::MakeWH(SkIntToScalar(100), SkIntToScalar(100));
@@ -72,7 +72,7 @@ public:
 protected:
 
     virtual SkString onShortName() { return SkString("chrome_gradtext2"); }
-    virtual SkISize onISize() { return make_isize(500, 480); }
+    virtual SkISize onISize() { return SkISize::Make(500, 480); }
     virtual void onDraw(SkCanvas* canvas) {
         SkPaint paint;
 
@@ -109,7 +109,7 @@ protected:
         return SkString("gradtext");
     }
 
-    virtual SkISize onISize() { return make_isize(500, 480); }
+    virtual SkISize onISize() { return SkISize::Make(500, 480); }
 
     static void draw_text(SkCanvas* canvas, const SkPaint& paint) {
         const char* text = "When in the course of human events";