Fix some inconsistent strings in zero state UMA metrics.

TBR=holte@chromium.org

Bug: 969200
Change-Id: I3ffd5d6382f680297dfe71d6554419711afe5cbc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1638881
Commit-Queue: Jenny Zhang <jennyz@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#665978}

ash/app_list/app_list_metrics.cc

@@ -61,12 +61,12 @@ constexpr char kAppListSearchResultOpenSourceHistogram[] =
 // The UMA hisotogram that logs the action user performs on zero state
 // search result.
 constexpr char kAppListZeroStateSearchResultUserActionHistogram[] =
-    "Apps.AppListZeroStateSearchResultUserActionType";
+    "Apps.AppList.ZeroStateSearchResultUserActionType";
 
 // The UMA histogram that logs user's decision(remove or cancel) for zero state
 // search result removal confirmation.
 constexpr char kAppListZeroStateSearchResultRemovalHistogram[] =
-    "Apps.ZeroStateSearchResutRemovalDecision";
+    "Apps.AppList.ZeroStateSearchResultRemovalDecision";
 
 // The UMA histogram that logs the length of the query when user abandons
 // results of a queried search or recommendations of zero state(zero length

tools/metrics/histograms/histograms.xml

@@ -4025,6 +4025,17 @@ uploading your change for review.
   </summary>
 </histogram>
 
+<histogram name="Apps.AppList.ZeroStateSearchResultRemovalDecision"
+    enum="AppListZeroStateResultRemovalConfirmation" expires_after="2019-12-31">
+  <owner>jennyz@chromium.org</owner>
+  <owner>newcomer@chromium.org</owner>
+  <summary>
+    The decision of the user whether to remove a zero state search result. This
+    is gathered per click of a remove or cancel button of a search result
+    removal confirmation dialog.
+  </summary>
+</histogram>
+
 <histogram name="Apps.AppList.ZeroStateSearchResultUserActionType"
     enum="AppListZeroStateSearchResultUserActionType"
     expires_after="2019-12-31">
@@ -4038,6 +4049,10 @@ uploading your change for review.
 
 <histogram name="Apps.AppList.ZeroStateSearchResutRemovalDecision"
     enum="AppListZeroStateResultRemovalConfirmation" expires_after="2019-12-31">
+  <obsolete>
+    Deprecated June 2019, replaced by
+    Apps.AppList.ZeroStateSearchResultRemovalDecision.
+  </obsolete>
   <owner>jennyz@chromium.org</owner>
   <owner>newcomer@chromium.org</owner>
   <summary>