Move full hash caching logic to v4_get_hash_protocol_manager

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 de0654004ee5c288b0d9d634c631dbe0d26d27e0..fa0371f2f76eeb1b7d9ac7ae657aa8a3a8fc6bfc 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -49624,12 +49624,6 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>Track cache hits for V4 full hashes.</summary>
 </histogram>
 
-<histogram name="SafeBrowsing.V4GetHashCheckResult"

[Nathan Parker, 2016/09/09 21:26:22]

I think we should be able to use this -- it's useful to know how often the
response has something that matches out full-hashes.

[vakh (use Gerrit instead), 2016/09/10 01:04:11]

Done.

-    enum="SafeBrowsingV4GetHashCheckResult">
-  <owner>kcarattini@chromium.org</owner>
-  <summary>Track get hash response hits for V4 full hash requests.</summary>
-</histogram>
-
 <histogram name="SafeBrowsing.V4StoreReadResult"
     enum="SafeBrowsingV4StoreReadResult">
   <owner>vakh@chromium.org</owner>
@@ -92528,12 +92522,6 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="2" label="FULL_HASH_NEGATIVE_CACHE_HIT"/>
 </enum>
 
-<enum name="SafeBrowsingV4GetHashCheckResult" type="int">
-  <int value="0" label="GET_HASH_CHECK_EMPTY"/>
-  <int value="1" label="GET_HASH_CHECK_HIT"/>
-  <int value="2" label="GET_HASH_CHECK_MISS"/>
-</enum>
-
 <enum name="SafeBrowsingV4OperationResult" type="int">
   <int value="0" label="STATUS_200"/>
   <int value="1" label="PARSE_ERROR (subset of STATUS_200)"/>