Add metrics for Flash ephemeral permissions.

A metric is added to count the number of times Flash permissions are
set for a website. The counter is separated based on whether this is the
first granting of permission or the next times.

Bug: 865933
Change-Id: If33aaf4915109f6e7ed49dc1e7142c64b6981fac
Reviewed-on: https://chromium-review.googlesource.com/1145197Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: Markus Heintz <markusheintz@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579759}

components/content_settings/core/browser/host_content_settings_map.cc

@@ -35,6 +35,7 @@
 #include "components/content_settings/core/browser/website_settings_registry.h"
 #include "components/content_settings/core/common/content_settings_pattern.h"
 #include "components/content_settings/core/common/content_settings_utils.h"
+#include "components/content_settings/core/common/features.h"
 #include "components/content_settings/core/common/pref_names.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_service.h"
@@ -187,6 +188,13 @@ content_settings::PatternPair GetPatternsForContentSettingsType(
   return patterns;
 }
 
+// This enum is used to collect Flash permission data.
+enum class FlashPermissions {
+  kFirstTime = 0,
+  kRepeated = 1,
+  kMaxValue = kRepeated,
+};
+
 }  // namespace
 
 HostContentSettingsMap::HostContentSettingsMap(PrefService* prefs,
@@ -510,6 +518,23 @@ void HostContentSettingsMap::SetContentSettingCustomScope(
   DCHECK(content_settings::ContentSettingsRegistry::GetInstance()->Get(
       content_type));
 
+  // Record stats on Flash permission grants with ephemeral storage.
+  if (content_type == CONTENT_SETTINGS_TYPE_PLUGINS &&
+      setting == CONTENT_SETTING_ALLOW &&
+      base::FeatureList::IsEnabled(
+          content_settings::features::kEnableEphemeralFlashPermission)) {
+    GURL url(primary_pattern.ToString());
+    ContentSettingsPattern temp_patterns[2];
+    std::unique_ptr<base::Value> value(GetContentSettingValueAndPatterns(
+        content_settings_providers_[PREF_PROVIDER].get(), url, url,
+        CONTENT_SETTINGS_TYPE_PLUGINS_DATA, resource_identifier, is_incognito_,
+        temp_patterns, temp_patterns + 1));
+
+    UMA_HISTOGRAM_ENUMERATION(
+        "ContentSettings.EphemeralFlashPermission",
+        value ? FlashPermissions::kRepeated : FlashPermissions::kFirstTime);
+  }
+
   std::unique_ptr<base::Value> value;
   // A value of CONTENT_SETTING_DEFAULT implies deleting the content setting.
   if (setting != CONTENT_SETTING_DEFAULT) {

tools/metrics/histograms/enums.xml

@@ -7221,6 +7221,11 @@ Called by update_net_error_codes.py.-->
   <int value="6" label="Clicked 'Always show on mobile'"/>
 </enum>
 
+<enum name="ContentSettings.EphemeralFlashPermission">
+  <int value="0" label="The First time permission is granted to a host."/>
+  <int value="1" label="Subsequant grants to a host."/>
+</enum>
+
 <enum name="ContentSettingScheme">
   <int value="0" label="(wildcard)"/>
   <int value="1" label="(other)"/>

tools/metrics/histograms/histograms.xml

@@ -13593,6 +13593,14 @@ uploading your change for review.
   </summary>
 </histogram>
 
+<histogram name="ContentSettings.EphemeralFlashPermission"
+    enum="ContentSettings.EphemeralFlashPermission" expires_after="M71">
+  <owner>rhalavati@chromium.org</owner>
+  <summary>
+    Records the number of times Flash permission is granted for a host.
+  </summary>
+</histogram>
+
 <histogram name="ContentSettings.Exceptions">
   <owner>lshang@chromium.org</owner>
   <summary>