Set maximum output size for scaled-image-cache images

include/core/SkGraphics.h

Index: include/core/SkGraphics.h
diff --git a/include/core/SkGraphics.h b/include/core/SkGraphics.h
index 2667a388d2bbb66a7081fe18bb053328fbdc9266..6d04280c7f2935384cc1cf22a5e3f57ed46ce537 100644
--- a/include/core/SkGraphics.h
+++ b/include/core/SkGraphics.h
@@ -84,6 +84,19 @@ public:
     static size_t SetImageCacheByteLimit(size_t newLimit);
 
     /**
+     *  Scaling bitmaps with the SkPaint::kHigh_FilterLevel setting is
+     *  expensive, so the result is saved in the global Scaled Image
+     *  Cache.  When the resulting bitmap is too large, this can
+     *  overload the cache.  If the ImageCacheSingleAllocationByteLimit
+     *  is set to a non-zero number, and the resulting bitmap would be
+     *  larger than that value, the bitmap scaling algorithm falls
+     *  back onto a cheaper algorithm and does not cache the result.
+     *  Zero is the default value.
+     */
+    static size_t GetImageCacheSingleAllocationByteLimit();
+    static size_t SetImageCacheSingleAllocationByteLimit(size_t newLimit);

[reveman, 2014/07/16 20:38:04]

I know this only affects pre-scaling of images and the comment also makes it
clear. The name of the function itself doesn't make this clear though.
SetImageCacheSingleAllocationByteLimit sounds like it might affect more than
pre-scaling. For example, decoded images and I wouldn't want to set this limit
in chrome if that was the case.

Maybe we just need some general comment making it clear that all these
"ImageCache" functions control caching of pre-scaled images.

Not a big deal, just wanted to point it out. As long as this does what we need,
I'm OK with it.

+
+    /**
      *  Applications with command line options may pass optional state, such
      *  as cache sizes, here, for instance:
      *  font-cache-limit=12345678