Add UMA statistics to the clipboard

ui/base/clipboard/clipboard.cc

Index: ui/base/clipboard/clipboard.cc
diff --git a/ui/base/clipboard/clipboard.cc b/ui/base/clipboard/clipboard.cc
index e384c6528d70dbc4bdd01ad8832b5704d1f3864e..75617b65145ccf9a23280e24eaac731ee329b1c3 100644
--- a/ui/base/clipboard/clipboard.cc
+++ b/ui/base/clipboard/clipboard.cc
@@ -9,6 +9,7 @@
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/metrics/histogram.h"
 #include "base/synchronization/lock.h"
 #include "ui/gfx/size.h"
 
@@ -103,6 +104,8 @@ union SourceTag2BinaryHelper {
 
 }  // namespace
 
+const Clipboard::SourceTag Clipboard::kInvalidSourceTag =
+    reinterpret_cast<void*>(1);
 const char Clipboard::kMimeTypeText[] = "text/plain";
 const char Clipboard::kMimeTypeURIList[] = "text/uri-list";
 const char Clipboard::kMimeTypeDownloadURL[] = "downloadurl";
@@ -186,6 +189,9 @@ void Clipboard::WriteObjects(Buffer buffer,
   WriteObjectsImpl(buffer, objects, tag);
   if (!write_objects_callback_.is_null())
     write_objects_callback_.Run(buffer);
+  ReportAction(buffer,
+                       tag == SourceTag() ? WRITE_CLIPBOARD_NO_SOURCE_TAG :

[tony, 2013/02/20 19:25:07]

Did you mean to wrap this line?  I normally line up the : below the ?, but
indenting is OK too.

[vasilii, 2013/02/21 10:36:01]

Done.

+                           WRITE_CLIPBOARD_SOURCE_TAG);
 }
 
 void Clipboard::DispatchObject(ObjectType type, const ObjectMapParams& params) {
@@ -299,4 +305,33 @@ void Clipboard::ReplaceSharedMemHandle(ObjectMap* objects,
   }
 }
 
+void Clipboard::ReportAction(Buffer buffer, TrackedActions action) const
+{
+  if (buffer != BUFFER_STANDARD)
+    return;
+
+  switch (action){

[battre, 2013/02/20 23:01:03]

nit: space before {

[vasilii, 2013/02/21 10:36:01]

Done.

+    case WRITE_CLIPBOARD_NO_SOURCE_TAG:
+    case WRITE_CLIPBOARD_SOURCE_TAG:
+      UMA_HISTOGRAM_ENUMERATION("Clipboard.Actions",
+                                action,
+                                MAX_TRACKED_ACTION);
+      break;
+    // The code below counts cases when there is the kInvalidSourceTag in the
+    // clipboard. That is, original data came from Incognito window and was
+    // destroyed with that window.
+    case READ_TEXT:
+    case READ_ASCII_TEXT:
+    case READ_RTF:
+      if (kInvalidSourceTag == ReadSourceTag(buffer)) {
+        UMA_HISTOGRAM_ENUMERATION("Clipboard.Actions",

[battre, 2013/02/20 23:01:03]

The UMA name indicates that it records the number of times something is done.
This is not the case with the current implementation. You don't report the
number of times, the clipboard is read here.

[vasilii, 2013/02/21 10:36:01]

Changed the name.

+                                  action,
+                                  MAX_TRACKED_ACTION);
+      }
+      break;
+    case MAX_TRACKED_ACTION:
+      break;
+  }
+}
+
 }  // namespace ui