Isolate initiation counts for downloads to their own histograms and improve

content/browser/download/download_stats.h

Index: content/browser/download/download_stats.h
diff --git a/content/browser/download/download_stats.h b/content/browser/download/download_stats.h
index ecf87f30f9e1172a8a45a4cb03146e2cd9b8b3c0..36d98975e284feb299ccc6c46ec14fd3b2d2b5e4 100644
--- a/content/browser/download/download_stats.h
+++ b/content/browser/download/download_stats.h
@@ -24,30 +24,15 @@ namespace download_stats {
 // We keep a count of how often various events occur in the
 // histogram "Download.Counts".
 enum DownloadCountTypes {
-  // The download was initiated by navigating to a URL (e.g. by user
-  // click).
-  // This is now unused, but left around so that the values don't change.
-  INITIATED_BY_NAVIGATION_COUNT = 0,
-
-  // The download was initiated by invoking a context menu within a page.
-  // This is now unused, but left around so that the values don't change.
-  INITIATED_BY_CONTEXT_MENU_COUNT,
-
-  // The download was initiated when the SavePackage system rejected
-  // a Save Page As ... by returning false from
-  // SavePackage::IsSaveableContents().
-  INITIATED_BY_SAVE_PACKAGE_FAILURE_COUNT,
-
-  // The download was initiated by a drag and drop from a drag-and-drop
-  // enabled web application.
-  INITIATED_BY_DRAG_N_DROP_COUNT,
-
-  // The download was initiated by explicit RPC from the renderer process
-  // (e.g. by Alt-click).
-  INITIATED_BY_RENDERER_COUNT,
-
-  // Downloads that made it to DownloadResourceHandler -- all of the
-  // above minus those blocked by DownloadThrottlingResourceHandler.
+  // Stale enum values left around so that values passed to UMA don't
+  // change.
+  DOWNLOAD_COUNT_UNUSED_0 = 0,
+  DOWNLOAD_COUNT_UNUSED_1,
+  DOWNLOAD_COUNT_UNUSED_2,
+  DOWNLOAD_COUNT_UNUSED_3,
+  DOWNLOAD_COUNT_UNUSED_4,
+
+  // Downloads that made it to DownloadResourceHandler
   UNTHROTTLED_COUNT,
 
   // Downloads that actually complete.
@@ -81,8 +66,33 @@ enum DownloadCountTypes {
   DOWNLOAD_COUNT_TYPES_LAST_ENTRY
 };
 
+enum DownloadInitiationSources {
+  // The download was initiated when the SavePackage system rejected
+  // a Save Page As ... by returning false from
+  // SavePackage::IsSaveableContents().

[cbentzel, 2012/02/06 19:57:29]

I don't love the name of "SAVE_PACKAGE_FAILURE" - makes it sound like there's a
problem, when really it's just non-HTML content. Not going to push hard against
the name, though.

[Randy Smith (Not in Mondays), 2012/02/07 18:20:18]

Nah, you're right, and more to the point, I think I can change the name without
messing up any histograms (as long as I leave the value the same).  

Done.

+  INITIATED_BY_SAVE_PACKAGE_FAILURE = 0,
+
+  // The download was initiated by a drag and drop from a drag-and-drop
+  // enabled web application.
+  INITIATED_BY_DRAG_N_DROP,
+
+  // The download was initiated by explicit RPC from the renderer process
+  // (e.g. by Alt-click) through the IPC ViewHostMsg_DownloadUrl.
+  INITIATED_BY_RENDERER,
+
+  // The download was initiated by a renderer or plugin process through
+  // the IPC ViewHostMsg_SaveURLAs.
+  INITIATED_BY_RENDERER_SAVE,
+
+  DOWNLOAD_INITIATION_SOURCES_LAST_ENTRY
+};
+
+
 // Increment one of the above counts.
-CONTENT_EXPORT void RecordDownloadCount(DownloadCountTypes type);
+void RecordDownloadCount(DownloadCountTypes type);
+
+// Record initiation of a download from a specific source.
+void RecordDownloadSource(DownloadInitiationSources source);
 
 // Record COMPLETED_COUNT and how long the download took.
 void RecordDownloadCompleted(const base::TimeTicks& start, int64 download_len);