Record the data use by content type

components/data_use_measurement/core/data_use_user_data.h

Index: components/data_use_measurement/core/data_use_user_data.h
diff --git a/components/data_use_measurement/core/data_use_user_data.h b/components/data_use_measurement/core/data_use_user_data.h
index cfae6b9b75c9c6c3e21d295005915ddb3064d387..eb91790d59f1f30bee3461146ef082c20b654626 100644
--- a/components/data_use_measurement/core/data_use_user_data.h
+++ b/components/data_use_measurement/core/data_use_user_data.h
@@ -52,6 +52,25 @@ class DataUseUserData : public base::SupportsUserData::Data {
     UPDATE_CLIENT,
   };
 
+  // Data use broken by content type. This enum must remain synchronized
+  // with the enum of the same name in metrics/histograms/histograms.xml.

[Mark P, 2016/12/22 21:40:29]

Please follow the guidelines here:
https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histo...

[Raj, 2016/12/22 23:14:37]

Done.

+  enum DataUseContentType {
+    MAIN_FRAME_HTML,
+    NON_MAIN_FRAME_HTML,
+    CSS,
+    IMAGE,
+    JAVASCRIPT,
+    FONT,
+    AUDIO_APPBACKGROUND,
+    AUDIO_TABBACKGROUND,
+    AUDIO,
+    VIDEO_APPBACKGROUND,
+    VIDEO_TABBACKGROUND,
+    VIDEO,
+    OTHER,

[Mark P, 2016/12/22 21:40:29]

Also, it's typical for people to put the unknown/other bucket first so that when
they add new elements later, it's not stuck in the middle somewhere.

[Raj, 2016/12/22 23:14:37]

Done.

+    TYPE_MAX,
+  };
+
   // The state of the application. Only available on Android and on other
   // platforms it is always FOREGROUND.
   enum AppState { UNKNOWN, BACKGROUND, FOREGROUND };
@@ -78,6 +97,12 @@ class DataUseUserData : public base::SupportsUserData::Data {
 
   void set_app_state(AppState app_state) { app_state_ = app_state; }
 
+  DataUseContentType content_type() { return content_type_; }
+
+  void set_content_type(DataUseContentType content_type) {
+    content_type_ = content_type;
+  }
+
   // The key for retrieving back this type of user data.
   static const void* const kUserDataKey;
 
@@ -87,6 +112,8 @@ class DataUseUserData : public base::SupportsUserData::Data {
   // App state when network access was performed for the request previously.
   AppState app_state_;
 
+  DataUseContentType content_type_;
+
   DISALLOW_COPY_AND_ASSIGN(DataUseUserData);
 };