[Contextual Search] Add metrics to track Taps before Open.

Adds several new histograms for Contextual Search to track:
The total number of taps before ever opening the promo panel,
the number of times the promo panel was opened, the number
of taps since any panel was opened, and information about the
search term resolution (protocol, and single/multi-word).

There's a downstream CL dependent on this change: https://chrome-internal-review.googlesource.com/#/c/216388/

BUG=477827

Review URL: https://codereview.chromium.org/1131653005

Cr-Commit-Position: refs/heads/master@{#330841}

chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchUma.java

@@ -21,7 +21,7 @@ import java.util.concurrent.TimeUnit;
  */
 public class ContextualSearchUma {
     // An invalid value for the number of taps remaining for the promo.  Must be negative.
-    public static final int PROMO_TAPS_REMAINING_INVALID = -1;
+    private static final int PROMO_TAPS_REMAINING_INVALID = -1;
 
     // Constants to use for the original selection gesture
     private static final boolean LONG_PRESS = false;
@@ -163,6 +163,16 @@ public class ContextualSearchUma {
     private static final int NOT_PREFETCHED = 2;
     private static final int PREFETCH_BOUNDARY = 3;
 
+    // Constants used to log UMA "enum" histograms for HTTP / HTTPS.
+    private static final int PROTOCOL_IS_HTTP = 0;
+    private static final int PROTOCOL_NOT_HTTP = 1;
+    private static final int PROTOCOL_BOUNDARY = 2;
+
+    // Constants used to log UMA "enum" histograms for single / multi-word.
+    private static final int RESOLVED_SINGLE_WORD = 0;
+    private static final int RESOLVED_MULTI_WORD = 1;
+    private static final int RESOLVED_BOUNDARY = 2;
+
 
     /**
      * Key used in maps from {state, reason} to state entry (exit) logging code.
@@ -410,21 +420,21 @@ public class ContextualSearchUma {
 
     /**
      * Logs the state of the Contextual Search preference. This function should be called if the
-     * Contextual Search feature is enabled, and will track the different preference settings
+     * Contextual Search feature is active, and will track the different preference settings
      * (disabled, enabled or uninitialized). Calling more than once is fine.
-     * This is deprecated; pass the number of taps remaining to logPreferenceState.
      */
-    @Deprecated
     public static void logPreferenceState() {
-        logPreferenceState(PROMO_TAPS_REMAINING_INVALID);
+        RecordHistogram.recordEnumeratedHistogram("Search.ContextualSearchPreferenceState",
+                getPreferenceValue(), PREFERENCE_HISTOGRAM_BOUNDARY);
     }
 
     /**
      * Logs the state of the Contextual Search preference. This function should be called if the
-     * Contextual Search feature is enabled, and will track the different preference settings
+     * Contextual Search feature is active, and will track the different preference settings
      * (disabled, enabled or uninitialized). Calling more than once is fine.
      * @param promoTapsRemaining The number of taps remaining, or -1 if not applicable.
      */
+    @Deprecated
     public static void logPreferenceState(int promoTapsRemaining) {
         RecordHistogram.recordEnumeratedHistogram("Search.ContextualSearchPreferenceState",
                 getPreferenceValue(), PREFERENCE_HISTOGRAM_BOUNDARY);
@@ -434,6 +444,90 @@ public class ContextualSearchUma {
         }
     }
 
+    /**
+     * Logs the given number of promo taps remaining.  Should be called only for users that
+     * are still undecided.
+     * @param promoTapsRemaining The number of taps remaining (should not be negative).
+     */
+    public static void logPromoTapsRemaining(int promoTapsRemaining) {
+        if (promoTapsRemaining >= 0) {
+            RecordHistogram.recordCountHistogram("Search.ContextualSearchPromoTapsRemaining",
+                    promoTapsRemaining);
+        }
+    }
+
+    /**
+     * Logs the historic number of times that a Tap gesture triggered the peeking promo
+     * for users that have never opened the panel.  This should be called periodically for
+     * undecided users only.
+     * @param promoTaps The historic number of taps that have caused the peeking bar for the promo,
+     *        for users that have never opened the panel.
+     */
+    public static void logPromoTapsForNeverOpened(int promoTaps) {
+        RecordHistogram.recordCountHistogram("Search.ContextualSearchPromoTapsForNeverOpened",
+                promoTaps);
+    }
+
+    /**
+     * Logs the historic number of times that a Tap gesture triggered the peeking promo before
+     * the user ever opened the panel.  This should be called periodically for all users.
+     * @param promoTaps The historic number of taps that have caused the peeking bar for the promo
+     *        before the first open of the panel, for all users that have ever opened the panel.
+     */
+    public static void logPromoTapsBeforeFirstOpen(int promoTaps) {
+        RecordHistogram.recordCountHistogram("Search.ContextualSearchPromosTapsBeforeFirstOpen",
+                promoTaps);
+    }
+
+    /**
+     * Records the total count of times the promo panel has *ever* been opened.  This should only
+     * be called when the user is still undecided.
+     * @param count The total historic count of times the panel has ever been opened for the
+     *        current user.
+     */
+    public static void logPromoOpenCount(int count) {
+        RecordHistogram.recordCountHistogram("Search.ContextualSearchPromoOpenCount", count);
+    }
+
+    /**
+     * Logs the number of taps that have been counted since the user last opened the panel, for
+     * undecided users.
+     * @param tapsSinceOpen The number of taps to log.
+     */
+    public static void logTapsSinceOpenForUndecided(int tapsSinceOpen) {
+        RecordHistogram.recordCountHistogram("Search.ContextualSearchTapsSinceOpenUndecided",
+                tapsSinceOpen);
+    }
+
+    /**
+     * Logs the number of taps that have been counted since the user last opened the panel, for
+     * decided users.
+     * @param tapsSinceOpen The number of taps to log.
+     */
+    public static void logTapsSinceOpenForDecided(int tapsSinceOpen) {
+        RecordHistogram.recordCountHistogram("Search.ContextualSearchTapsSinceOpenDecided",
+                tapsSinceOpen);
+    }
+
+    /**
+     * Logs whether the Search Term was single or multiword.
+     * @param isSingleWord Whether the resolved search term is a single word or not.
+     */
+    public static void logSearchTermResolvedWords(boolean isSingleWord) {
+        RecordHistogram.recordEnumeratedHistogram("Search.ContextualSearchResolvedTermWords",
+                isSingleWord ? RESOLVED_SINGLE_WORD : RESOLVED_MULTI_WORD, RESOLVED_BOUNDARY);
+    }
+
+    /**
+     * Logs whether the base page was using the HTTP protocol or not.
+     * @param isHttpBasePage Whether the base page was using the HTTP protocol or not (should
+     *        be false for HTTPS or other URIs).
+     */
+    public static void logBasePageProtocol(boolean isHttpBasePage) {
+        RecordHistogram.recordEnumeratedHistogram("Search.ContextualSearchBasePageProtocol",
+                isHttpBasePage ? PROTOCOL_IS_HTTP : PROTOCOL_NOT_HTTP, PROTOCOL_BOUNDARY);
+    }
+
     /**
      * Logs changes to the Contextual Search preference, aside from those resulting from the first
      * run flow.
@@ -444,16 +538,6 @@ public class ContextualSearchUma {
                 enabled ? PREFERENCE_ENABLED : PREFERENCE_DISABLED, PREFERENCE_HISTOGRAM_BOUNDARY);
     }
 
-    /**
-     * Logs the outcome of a first run flow.
-     * This is deprecated; call logPromoOutcome instead.
-     */
-    @Deprecated
-    public static void logFirstRunFlowOutcome() {
-        RecordHistogram.recordEnumeratedHistogram("Search.ContextualSearchFirstRunFlowOutcome",
-                getPreferenceValue(), PREFERENCE_HISTOGRAM_BOUNDARY);
-    }
-
     /**
      * Logs the outcome of the promo (first run flow).
      * Logs multiple histograms; with and without the originating gesture.