cc: Fix BytesPerPixel issue and refactor.

cc/resources/resource.h

Index: cc/resources/resource.h
diff --git a/cc/resources/resource.h b/cc/resources/resource.h
index f9138fbb876ef405c8afada390cf4031f92f4b92..d0c60599dea44dc766804fcda8552882be46f59f 100644
--- a/cc/resources/resource.h
+++ b/cc/resources/resource.h
@@ -51,8 +51,9 @@ class CC_EXPORT Resource {
   inline static size_t UncheckedMemorySizeBytes(const gfx::Size& size,
                                                 ResourceFormat format) {
     DCHECK(VerifySizeInBytes(size, format));
-    return static_cast<size_t>(BitsPerPixel(format)) * size.width() *
-           size.height() / 8;

[reveman, 2015/06/24 18:02:26]

hm, looks like this was broken for height < 8 before this, that's pretty bad.

[vmpstr, 2015/06/24 18:46:14]

I think the order of multiplicative operations is well defined to be left to
right, so this was probably OK. 

+    return (static_cast<size_t>(BitsPerPixel(format)) * size.width() *
+            size.height()) /
+           8;

[reveman, 2015/06/24 18:02:26]

Can you add a temporary bytes_per_row variable here to make this a bit easier to
read?

   }
 
  protected: