| Index: tools/metrics/histograms/histograms.xml | 
| diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml | 
| index ec03e58ec6d168eb277dc84930a1802f28dd51b0..dd4f64eae26203479e49f6df2fe33cc03784d083 100644 | 
| --- a/tools/metrics/histograms/histograms.xml | 
| +++ b/tools/metrics/histograms/histograms.xml | 
| @@ -12928,6 +12928,9 @@ Therefore, the affected-histogram name has to have at least one dot in it. | 
| </histogram> | 
|  | 
| <histogram name="HttpCache.AsyncValidationDuration" units="milliseconds"> | 
| +  <obsolete> | 
| +    Deprecated as of 3/2015. | 
| +  </obsolete> | 
| <owner>ricea@chromium.org</owner> | 
| <summary> | 
| The time spent performing an asynchronous revalidation that was triggered by | 
|  |