Add new memory histograms which fix inprecise bucketing.

base/metrics/histogram_macros.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_METRICS_HISTOGRAM_MACROS_H_
 #define BASE_METRICS_HISTOGRAM_MACROS_H_
 
 #include "base/atomicops.h"
 #include "base/basictypes.h"
 #include "base/logging.h"
@@ skipping 188 matching lines @@
     STATIC_HISTOGRAM_POINTER_BLOCK(name, Add(sample), \
         base::Histogram::FactoryGet(name, min, max, bucket_count, \
             base::HistogramBase::kUmaTargetedHistogramFlag))
 
 #define UMA_HISTOGRAM_MEMORY_KB(name, sample) UMA_HISTOGRAM_CUSTOM_COUNTS( \
     name, sample, 1000, 500000, 50)
 
 #define UMA_HISTOGRAM_MEMORY_MB(name, sample) UMA_HISTOGRAM_CUSTOM_COUNTS( \
     name, sample, 1, 1000, 50)
 
+#define UMA_HISTOGRAM_MEMORY_LARGE_MB(name, sample) \
+    UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, 1, 64000, 100)
+
 #define UMA_HISTOGRAM_PERCENTAGE(name, under_one_hundred) \
     UMA_HISTOGRAM_ENUMERATION(name, under_one_hundred, 101)
 
 #define UMA_HISTOGRAM_BOOLEAN(name, sample) \
     STATIC_HISTOGRAM_POINTER_BLOCK(name, AddBoolean(sample), \
         base::BooleanHistogram::FactoryGet(name, \
             base::HistogramBase::kUmaTargetedHistogramFlag))
 
 // The samples should always be strictly less than |boundary_value|.  For more
 // details, see the comment for the |LOCAL_HISTOGRAM_ENUMERATION| macro, above.
@@ skipping 39 matching lines @@
         UMA_HISTOGRAM_LONG_TIMES_100(name, elapsed); \
       } else { \
         UMA_HISTOGRAM_TIMES(name, elapsed); \
       } \
     } \
    private: \
     base::TimeTicks constructed_; \
   } scoped_histogram_timer_##key
 
 #endif  // BASE_METRICS_HISTOGRAM_MACROS_H_