Add detailed UMA metrics for v4_store, broken down by storeid.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 06d5f2f5add148c2fd2a891efcb7516ba4c9c778..ff35365ada02cee4e3beea65f83312c6a8c2bcf5 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -51181,7 +51181,7 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4AddUnlumpedHashesTime" units="ms">
+<histogram name="SafeBrowsing.V4AddUnlumpedHashes.Time" units="ms">
   <owner>vakh@chromium.org</owner>
   <summary>
     Records the time it takes to copy the SafeBrowsing list update as a string,
@@ -51190,43 +51190,107 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4ApplyUpdateResult"
+<histogram name="SafeBrowsing.V4FullHashCacheResult"
+    enum="SafeBrowsingV4FullHashCacheResult">
+  <owner>kcarattini@chromium.org</owner>
+  <owner>vakh@chromium.org</owner>
+  <summary>Track cache hits for V4 full hashes.</summary>
+</histogram>
+
+<histogram name="SafeBrowsing.V4GetHashCheckResult"
+    enum="SafeBrowsingV4GetHashCheckResult">
+  <owner>kcarattini@chromium.org</owner>
+  <owner>vakh@chromium.org</owner>
+  <summary>Track get hash response hits for V4 full hash requests.</summary>
+</histogram>
+
+<histogram name="SafeBrowsing.V4MergeUpdate.Time" units="ms">
+  <owner>vakh@chromium.org</owner>
+  <summary>
+    Records the time it takes to merge the existing state of the list with the
+    update. The update may have been received from the server, or it may have
+    just been read from disk.
+  </summary>
+</histogram>
+
+<histogram name="SafeBrowsing.V4ProcessFullUpdate.ApplyUpdate.Result"
     enum="SafeBrowsingV4ApplyUpdateResult">
   <owner>vakh@chromium.org</owner>
   <summary>
-    Track the result of applying the update fetched from the PVer4 service for a
-    particular store.
+    Track the result of applying a full update for a store received from PVer4
+    SafeBrowsing service.
+  </summary>
+</histogram>
+
+<histogram name="SafeBrowsing.V4ProcessFullUpdate.DecodeAdditions.Result"
+    enum="SafeBrowsingV4DecodeResult">
+  <owner>vakh@chromium.org</owner>
+  <summary>
+    Track the result of decoding the Rice-encoded list of additions of 4-byte
+    hash prefixes. This is logged once per store, per update containing
+    Rice-encoded additions. This histogram is specific to processing full
+    updates received from the server.
+  </summary>
+</histogram>
+
+<histogram name="SafeBrowsing.V4ProcessFullUpdate.DecodeAdditions.Time"
+    units="ms">
+  <owner>vakh@chromium.org</owner>
+  <summary>
+    Records the time it takes to decode the Rice-encoded additions to the
+    blacklist into raw format when applying a full update to a store.
+  </summary>
+</histogram>
+
+<histogram name="SafeBrowsing.V4ProcessFullUpdate.MergeUpdate.Time" units="ms">
+  <owner>vakh@chromium.org</owner>
+  <summary>
+    Records the time it takes to merge the existing state of the list with a
+    full update received from the server.
+  </summary>
+</histogram>
+
+<histogram name="SafeBrowsing.V4ProcessFullUpdate.Time" units="ms">
+  <owner>vakh@chromium.org</owner>
+  <summary>
+    Records the time it takes to process a SafeBrowsing list full update. It
+    includes V4AddUnlumpedHashes.Time for each prefix-sized list, and
+    V4ProcessFullUpdate.MergeUpdate.Time. Additionally, if the update is
+    Rice-encoded, it includes V4ProcessFullUpdate.DecodeAdditions.Time for each
+    prefix-sized list that's Rice-encoded.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4ApplyUpdateResultWhenReadingFromDisk"
+<histogram name="SafeBrowsing.V4ProcessPartialUpdate.ApplyUpdate.Result"
     enum="SafeBrowsingV4ApplyUpdateResult">
   <owner>vakh@chromium.org</owner>
   <summary>
-    Track the result of applying an update read from disk after parsing it
-    successfully as a protobuf.
+    Track the result of applying a partial update for a store received from
+    PVer4 SafeBrowsing service.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4DecodeAdditionsResult"

[Steven Holte, 2016/10/10 22:04:28]

Don't remove the old histogram descriptions, since they will still be reported
by older versions of chrome.  Instead, mark them as obsolete.

[vakh (use Gerrit instead), 2016/10/10 22:15:59]

The old ones were added fairly recently by me and I don't intend to track them
going forward. Even in this case should they be marked as obsolete?

[Steven Holte, 2016/10/12 01:03:48]

Leaving them in at least means that these don't show up as unknown values in
histogram eraser.  This file is overdue for some cleanup, so we'll probably need
to do something to trim obsolete histograms soon, but if you leave them in as
obsolete they can get picked up in whatever that cleanup ends up doing.

+<histogram name="SafeBrowsing.V4ProcessPartialUpdate.DecodeAdditions.Result"
     enum="SafeBrowsingV4DecodeResult">
   <owner>vakh@chromium.org</owner>
   <summary>
     Track the result of decoding the Rice-encoded list of additions of 4-byte
     hash prefixes. This is logged once per store, per update containing
-    Rice-encoded additions.
+    Rice-encoded additions. This histogram is specific to processing partial
+    updates received from the server.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4DecodeAdditionsTime" units="ms">
+<histogram name="SafeBrowsing.V4ProcessPartialUpdate.DecodeAdditions.Time"
+    units="ms">
   <owner>vakh@chromium.org</owner>
   <summary>
     Records the time it takes to decode the Rice-encoded additions to the
-    blacklist into raw format.
+    blacklist into raw format when applying a partial update to a store.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4DecodeRemovalsResult"
+<histogram name="SafeBrowsing.V4ProcessPartialUpdate.DecodeRemovals.Result"
     enum="SafeBrowsingV4DecodeResult">
   <owner>vakh@chromium.org</owner>
   <summary>
@@ -51236,70 +51300,84 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4DecodeRemovalsTime" units="ms">
+<histogram name="SafeBrowsing.V4ProcessPartialUpdate.DecodeRemovals.Time"
+    units="ms">
   <owner>vakh@chromium.org</owner>
   <summary>
     Records the time it takes to decode the Rice-encoded removals from the
-    blacklist into raw format.
+    blacklist into raw format when applying a partial update to a store.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4FullHashCacheResult"
-    enum="SafeBrowsingV4FullHashCacheResult">
-  <owner>kcarattini@chromium.org</owner>
+<histogram name="SafeBrowsing.V4ProcessPartialUpdate.MergeUpdate.Time"
+    units="ms">
   <owner>vakh@chromium.org</owner>
-  <summary>Track cache hits for V4 full hashes.</summary>
+  <summary>
+    Records the time it takes to merge the existing state of the list with a
+    partial update received from the server.
+  </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4GetHashCheckResult"
-    enum="SafeBrowsingV4GetHashCheckResult">
-  <owner>kcarattini@chromium.org</owner>
+<histogram name="SafeBrowsing.V4ProcessPartialUpdate.Time" units="ms">
   <owner>vakh@chromium.org</owner>
-  <summary>Track get hash response hits for V4 full hash requests.</summary>
+  <summary>
+    Records the time it takes to process a SafeBrowsing list partial update. It
+    includes V4AddUnlumpedHashes.Time for each prefix-sized list, and
+    V4MergeUpdate.Time. Additionally, if the update is Rice-encoded, it includes
+    V4ProcessPartialUpdate.DecodeRemovals.Time, and
+    V4ProcessPartialUpdate.DecodeAdditions.Time for each prefix-sized list
+    that's Rice-encoded.
+  </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4MergeUpdateTime" units="ms">
+<histogram name="SafeBrowsing.V4ReadFromDisk.ApplyUpdate.Result"
+    enum="SafeBrowsingV4ApplyUpdateResult">
   <owner>vakh@chromium.org</owner>
   <summary>
-    Records the time it takes to merge the existing state of the list with the
-    update. The update may have been received from the server, or it may have
-    just been read from disk.
+    Track the result of applying an ListUpdateResponse read from disk after
+    parsing it successfully as a protobuf.
+  </summary>
+</histogram>
+
+<histogram name="SafeBrowsing.V4ReadFromDisk.DecodeAdditions.Result"
+    enum="SafeBrowsingV4DecodeResult">
+  <owner>vakh@chromium.org</owner>
+  <summary>
+    Track the result of decoding the Rice-encoded list of additions of 4-byte
+    hash prefixes. This is logged once per store, per Chrome launch. It is
+    specific to processing V4StoreFileFormat proto read from disk.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4ProcessFullUpdateTime" units="ms">
+<histogram name="SafeBrowsing.V4ReadFromDisk.DecodeAdditions.Time" units="ms">
   <owner>vakh@chromium.org</owner>
   <summary>
-    Records the time it takes to process a SafeBrowsing list full update. It
-    includes V4AddUnlumpedHashesTime for each prefix-sized list, and
-    V4MergeUpdateTime. Additionally, if the update is Rice-encoded, it includes
-    V4DecodeAdditionsTime for each prefix-sized list that's Rice-encoded.
+    Records the time it takes to decode the Rice-encoded additions to the
+    blacklist into raw format when reading a store file from disk.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4ProcessPartialUpdateTime" units="ms">
+<histogram name="SafeBrowsing.V4ReadFromDisk.MergeUpdate.Time" units="ms">
   <owner>vakh@chromium.org</owner>
   <summary>
-    Records the time it takes to process a SafeBrowsing list partial update. It
-    includes V4AddUnlumpedHashesTime for each prefix-sized list, and
-    V4MergeUpdateTime. Additionally, if the update is Rice-encoded, it includes
-    V4DecodeRemovalsTime, and V4DecodeAdditionsTime for each prefix-sized list
-    that's Rice-encoded.
+    Records the time it takes to perform in-memory copy of the map of raw hash
+    prefixes read from disk.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4ReadFromDiskTime" units="ms">
+<histogram name="SafeBrowsing.V4ReadFromDisk.Time" units="ms">
   <owner>vakh@chromium.org</owner>
   <summary>
     Records the time it takes to read, parse, and process a SafeBrowsing list
     stored on disk. This happens at Chromium start-up. It includes
-    V4AddUnlumpedHashesTime for each prefix-sized list, and V4MergeUpdateTime.
-    Additionally, if the file is Rice-encoded, it includes V4DecodeAdditionsTime
-    for each prefix-sized list that's Rice-encoded.
+    V4AddUnlumpedHashes.Time for each prefix-sized list, and V4MergeUpdate.Time.
+    Additionally, if the file is Rice-encoded, it includes
+    V4ReadFromDisk.DecodeAdditions.Time for each prefix-sized list that's
+    Rice-encoded.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4StoreReadResult"
+<histogram name="SafeBrowsing.V4StoreRead.Result"
     enum="SafeBrowsingV4StoreReadResult">
   <owner>vakh@chromium.org</owner>
   <summary>
@@ -51316,7 +51394,7 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4StoreWriteResult"
+<histogram name="SafeBrowsing.V4StoreWrite.Result"
     enum="SafeBrowsingV4StoreWriteResult">
   <owner>vakh@chromium.org</owner>
   <summary>