Addressed Windows compiler complaints

http://codereview.appspot.com/6462062/

This CL will require re-baselining of the imagemagnifier GM



git-svn-id: http://skia.googlecode.com/svn/trunk@5108 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tools/PictureRenderer.cpp b/tools/PictureRenderer.cpp
index 6af1218..f0aba9f 100644
--- a/tools/PictureRenderer.cpp
+++ b/tools/PictureRenderer.cpp
@@ -76,10 +76,10 @@
     this->INHERITED::init(pict);
 
     if (fTileWidthPercentage > 0) {
-        fTileWidth = sk_float_ceil2int(fTileWidthPercentage * fPicture->width() / 100);
+        fTileWidth = sk_float_ceil2int(float(fTileWidthPercentage * fPicture->width() / 100));
     }
     if (fTileHeightPercentage > 0) {
-        fTileHeight = sk_float_ceil2int(fTileHeightPercentage * fPicture->height() / 100);
+        fTileHeight = sk_float_ceil2int(float(fTileHeightPercentage * fPicture->height() / 100));
     }
 
     this->setupTiles();