Add Histogram Macros to Skia

include/config/SkUserConfig.h

Index: include/config/SkUserConfig.h
diff --git a/include/config/SkUserConfig.h b/include/config/SkUserConfig.h
index ff8a5f31541eb821df212f5e2ecafff52dca2979..583ac51694d8a8b24394cf9b31b30523676e63ab 100644
--- a/include/config/SkUserConfig.h
+++ b/include/config/SkUserConfig.h
@@ -153,4 +153,12 @@
  */
 //#define SK_PDF_USE_PATHOPS_CLIPPING
 
+/* Skia makes use of several histogram logging macros to trace the frequency
+ * of certain events. By default, Skia provides no-op versions of these
+ * macros in SkHistogramLogging.h. If a consumer has a histogram/metric
+ * collection backend, it may provide a custom header with their own
+ * definitions of these macros.
+ */
+//#define SK_HISTOGRAM_LOGGING_CUSTOM_SETUP_HEADER

[bsalomon, 2016/02/01 21:18:08]

I believe Chrome already uses a custom SkUseConfig file. Perhaps they could
override the macros there and Skia could set the defaults in SkPostConfig.h?

[ericrk, 2016/02/01 21:58:33]

hmmm... yeah, Chrome has an SkUserConfig file, that's where I was putting the
SK_HISTOGRAM_LOGGING_CUSTOM_SETUP_HEADER define... I can put the macros there
directly, but that ends up pulling more #includes into SkUserConfig, forcing
every file in Skia to pull in the histogram headers for chrome. This approach
overrides the values in a specific include file, so only those files that make
use of the histogram macros need to pay the cost of the include... not sure if
it really matters though, and I'm happy with either option - let me know what
you think.

+
 #endif