Put histogram code in disk_cache on a diet.

net/disk_cache/blockfile/histogram_macros_v3.h

Index: net/disk_cache/blockfile/histogram_macros_v3.h
diff --git a/net/disk_cache/blockfile/histogram_macros_v3.h b/net/disk_cache/blockfile/histogram_macros_v3.h
index e992a7c3f6950d6d8dfb82dfc39b2fa97e3371b3..5b23d420c2e5cda14b0955f71be9af057f04a4fc 100644
--- a/net/disk_cache/blockfile/histogram_macros_v3.h
+++ b/net/disk_cache/blockfile/histogram_macros_v3.h
@@ -17,11 +17,14 @@
 // whenever the name changes (the experiment group changes), the histrogram
 // object is re-created.
 // Note: These macros are only run on one thread, so the declarations of

[gavinp, 2014/03/17 15:06:28]

Nit: I would just eliminate this entire comment here, because it seems to be
recapitulating some history of how we wrote this. But I think that's a minor
style thing, so take it or leave it.

-// |counter| was made static (i.e., there will be no race for reinitialization).
+// |counter| could be static (since there will be no race for reinitialization),
+// but as they are used (with new names every time) in CACHE_UMA that
+// would not work and if CACHE_UMA is made to have one instance for every
+// cache, they will generate too much non-reusable machine code.
 
 #define CACHE_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, bucket_count) \
     do { \
-      static base::HistogramBase* counter(NULL); \
+      base::HistogramBase* counter(NULL); \
       if (!counter || name != counter->histogram_name()) \
         counter = base::Histogram::FactoryGet( \
             name, min, max, bucket_count, \
@@ -40,7 +43,7 @@
 
 #define CACHE_HISTOGRAM_CUSTOM_TIMES(name, sample, min, max, bucket_count) \
     do { \
-      static base::HistogramBase* counter(NULL); \
+      base::HistogramBase* counter(NULL); \
       if (!counter || name != counter->histogram_name()) \
         counter = base::Histogram::FactoryTimeGet( \
             name, min, max, bucket_count, \
@@ -53,7 +56,7 @@
     base::TimeDelta::FromSeconds(10), 50)
 
 #define CACHE_HISTOGRAM_ENUMERATION(name, sample, boundary_value) do { \
-    static base::HistogramBase* counter(NULL); \
+    base::HistogramBase* counter(NULL); \
     if (!counter || name != counter->histogram_name()) \
       counter = base::LinearHistogram::FactoryGet( \
                     name, 1, boundary_value, boundary_value + 1, \
@@ -95,25 +98,7 @@
 #define CACHE_UMA(type, name, sample) {\
     const std::string my_name =\
         CACHE_UMA_BACKEND_IMPL_OBJ->HistogramName(name);\
-    switch (CACHE_UMA_BACKEND_IMPL_OBJ->cache_type()) {\
-      case net::DISK_CACHE:\
-        CACHE_HISTOGRAM_##type(my_name.data(), sample);\
-        break;\
-      case net::MEDIA_CACHE:\
-        CACHE_HISTOGRAM_##type(my_name.data(), sample);\
-        break;\
-      case net::APP_CACHE:\
-        CACHE_HISTOGRAM_##type(my_name.data(), sample);\
-        break;\
-      case net::SHADER_CACHE:\
-        CACHE_HISTOGRAM_##type(my_name.data(), sample);\
-        break;\
-      case net::PNACL_CACHE:\
-        CACHE_HISTOGRAM_##type(my_name.data(), sample);\
-        break;\
-      default:\
-        break;\
-    }\
+    CACHE_HISTOGRAM_##type(my_name.data(), sample);\
   }
 
 #endif  // NET_DISK_CACHE_BLOCKFILE_HISTOGRAM_MACROS_V3_H_