Add leakDetectionMetric for tracing

tracing/tracing/metrics/system_health/memory_metric.html

Index: tracing/tracing/metrics/system_health/memory_metric.html
diff --git a/tracing/tracing/metrics/system_health/memory_metric.html b/tracing/tracing/metrics/system_health/memory_metric.html
index 2e4777061e56977099b6021e8f8b97e02c0dc73e..4cb0ab377f6f9bb3ba7a81b026afa7bc080e99c9 100644
--- a/tracing/tracing/metrics/system_health/memory_metric.html
+++ b/tracing/tracing/metrics/system_health/memory_metric.html
@@ -11,6 +11,7 @@ found in the LICENSE file.
 <link rel="import" href="/tracing/base/utils.html">
 <link rel="import" href="/tracing/extras/chrome/chrome_processes.html">
 <link rel="import" href="/tracing/metrics/metric_registry.html">
+<link rel="import" href="/tracing/metrics/system_health/utils.html">
 <link rel="import" href="/tracing/model/container_memory_dump.html">
 <link rel="import" href="/tracing/model/helpers/chrome_model_helper.html">
 <link rel="import" href="/tracing/model/memory_allocator_dump.html">
@@ -57,75 +58,12 @@ tr.exportTo('tr.metrics.sh', function() {
     const rangeOfInterest =
       opt_options ? opt_options.rangeOfInterest : undefined;
     const browserNameToGlobalDumps =
-        splitGlobalDumpsByBrowserName(model, rangeOfInterest);
+        tr.metrics.sh.splitGlobalDumpsByBrowserName(model, rangeOfInterest);
     addGeneralMemoryDumpValues(browserNameToGlobalDumps, values);
     addDetailedMemoryDumpValues(browserNameToGlobalDumps, values);
     addMemoryDumpCountValues(browserNameToGlobalDumps, values);
   }
 
-  /**
-   * Splits the global memory dumps in |model| by browser name.
-   *
-   * @param {!tr.Model} model The trace model from which the global dumps
-   *     should be extracted.
-   * @param {!tr.b.math.Range=} opt_rangeOfInterest If provided, global memory
-   *     dumps that do not inclusively intersect the range will be skipped.
-   * @return {!Map<string, !Array<!tr.model.GlobalMemoryDump>} A map from
-   *     browser names to the associated global memory dumps.
-   */
-  function splitGlobalDumpsByBrowserName(model, opt_rangeOfInterest) {
-    const chromeModelHelper =
-        model.getOrCreateHelper(tr.model.helpers.ChromeModelHelper);
-    const browserNameToGlobalDumps = new Map();
-    const globalDumpToBrowserHelper = new WeakMap();
-
-    // 1. For each browser process in the model, add its global memory dumps to
-    // |browserNameToGlobalDumps|. |chromeModelHelper| can be undefined if
-    // it fails to find any browser, renderer or GPU process (see
-    // tr.model.helpers.ChromeModelHelper.supportsModel).
-    if (chromeModelHelper) {
-      chromeModelHelper.browserHelpers.forEach(function(helper) {
-        // Retrieve the associated global memory dumps and check that they
-        // haven't been classified as belonging to another browser process.
-        const globalDumps = skipDumpsThatDoNotIntersectRange(
-            helper.process.memoryDumps.map(d => d.globalMemoryDump),
-            opt_rangeOfInterest);
-        globalDumps.forEach(function(globalDump) {
-          const existingHelper = globalDumpToBrowserHelper.get(globalDump);
-          if (existingHelper !== undefined) {
-            throw new Error('Memory dump ID clash across multiple browsers ' +
-                'with PIDs: ' + existingHelper.pid + ' and ' + helper.pid);
-          }
-          globalDumpToBrowserHelper.set(globalDump, helper);
-        });
-
-        makeKeyUniqueAndSet(browserNameToGlobalDumps,
-            tr.e.chrome.chrome_processes.canonicalizeName(helper.browserName),
-            globalDumps);
-      });
-    }
-
-    // 2. If any global memory dump does not have any associated browser
-    // process for some reason, associate it with an 'unknown_browser' browser
-    // so that we don't lose the data.
-    const unclassifiedGlobalDumps = skipDumpsThatDoNotIntersectRange(
-        model.globalMemoryDumps.filter(g => !globalDumpToBrowserHelper.has(g)),
-        opt_rangeOfInterest);
-    if (unclassifiedGlobalDumps.length > 0) {
-      makeKeyUniqueAndSet(
-          browserNameToGlobalDumps, 'unknown_browser', unclassifiedGlobalDumps);
-    }
-
-    return browserNameToGlobalDumps;
-  }
-
-  function skipDumpsThatDoNotIntersectRange(dumps, opt_range) {
-    if (!opt_range) return dumps;
-    return dumps.filter(d => opt_range.intersectsExplicitRangeInclusive(
-        d.start, d.end));
-  }
-
-
   const USER_FRIENDLY_BROWSER_NAMES = {
     'chrome': 'Chrome',
     'webview': 'WebView',
@@ -184,36 +122,6 @@ tr.exportTo('tr.metrics.sh', function() {
     }
   }
 
-  /**
-   * Function for adding entries with duplicate keys to a map without
-   * overriding existing entries.
-   *
-   * This is achieved by appending numeric indices (2, 3, 4, ...) to duplicate
-   * keys. Example:
-   *
-   *   const map = new Map();
-   *   // map = Map {}.
-   *
-   *   makeKeyUniqueAndSet(map, 'key', 'a');
-   *   // map = Map {"key" => "a"}.
-   *
-   *   makeKeyUniqueAndSet(map, 'key', 'b');
-   *   // map = Map {"key" => "a", "key2" => "b"}.
-   *                                ^^^^
-   *   makeKeyUniqueAndSet(map, 'key', 'c');
-   *   // map = Map {"key" => "a", "key2" => "b", "key3" => "c"}.
-   *                                ^^^^           ^^^^
-   */
-  function makeKeyUniqueAndSet(map, key, value) {
-    let uniqueKey = key;
-    let nextIndex = 2;
-    while (map.has(uniqueKey)) {
-      uniqueKey = key + nextIndex;
-      nextIndex++;
-    }
-    map.set(uniqueKey, value);
-  }
-
   /**
    * Add general memory dump values calculated from all global memory dumps to
    * |values|. In particular, this function adds the following values: