Update chrome.metricsPrivate externs and make closure fixes

chrome/test/data/extensions/api_test/metrics/test.js

Index: chrome/test/data/extensions/api_test/metrics/test.js
diff --git a/chrome/test/data/extensions/api_test/metrics/test.js b/chrome/test/data/extensions/api_test/metrics/test.js
index 4f2b264d8b73df9e7109fef66bf011fe696c9ff2..ab801e220287d1a0bd5ad208ffb412e1ccf2e8fb 100644
--- a/chrome/test/data/extensions/api_test/metrics/test.js
+++ b/chrome/test/data/extensions/api_test/metrics/test.js
@@ -23,7 +23,7 @@ chrome.test.runTests([
   function recordValue() {
     chrome.metricsPrivate.recordValue({
       'metricName': 'test.h.1',
-      'type': 'histogram-log',
+      'type': chrome.metricsPrivate.MetricTypeType.HISTOGRAM_LOG,
       'min': 1,
       'max': 100,
       'buckets': 50
@@ -31,7 +31,7 @@ chrome.test.runTests([
 
     chrome.metricsPrivate.recordValue({
       'metricName': 'test.h.2',
-      'type': 'histogram-linear',
+      'type': chrome.metricsPrivate.MetricTypeType.HISTOGRAM_LINEAR,
       'min': 1,
       'max': 200,
       'buckets': 50
@@ -108,28 +108,28 @@ chrome.test.runTests([
   function testBucketSizeChanges() {
     var linear1 = {
       'metricName': 'test.bucketchange.linear',
-      'type': 'histogram-linear',
+      'type': chrome.metricsPrivate.MetricTypeType.HISTOGRAM_LINEAR,
       'min': 0,
       'max': 100,
       'buckets': 10
     };
     var linear2 = {
       'metricName': 'test.bucketchange.linear',
-      'type': 'histogram-linear',
+      'type': chrome.metricsPrivate.MetricTypeType.HISTOGRAM_LINEAR,
       'min': 0,
       'max': 100,
       'buckets': 20
     };
     var log1 = {
       'metricName': 'test.bucketchange.log',
-      'type': 'histogram-log',
+      'type': chrome.metricsPrivate.MetricTypeType.HISTOGRAM_LOG,
       'min': 0,
       'max': 100,
       'buckets': 10
     };
     var log2 = {
       'metricName': 'test.bucketchange.log',
-      'type': 'histogram-log',
+      'type': chrome.metricsPrivate.MetricTypeType.HISTOGRAM_LOG,
       'min': 0,
       'max': 100,
       'buckets': 20