cros: Record metrics for placeholder strings

UX/PM want to see how often placeholder strings are shown
in Clipboard History. We may design a better solution if they are seen a
lot.

Bug: 1156837
Change-Id: If96e86d244cd05abcbd098ea19e9af0234928046
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2590753
Commit-Queue: Alex Newcomer <newcomer@chromium.org>
Reviewed-by: Weilun Shi <sweilun@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#839477}

ash/clipboard/clipboard_history_resource_manager.cc

@@ -11,6 +11,7 @@
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "base/bind.h"
 #include "base/containers/contains.h"
+#include "base/metrics/histogram_functions.h"
 #include "base/notreached.h"
 #include "base/stl_util.h"
 #include "base/strings/escape.h"
@@ -36,6 +37,17 @@ constexpr int kPlaceholderImageHeight = 74;
 constexpr int kPlaceholderImageOutlineCornerRadius = 8;
 constexpr int kPlaceholderImageSVGSize = 32;
 
+// Used in histograms, each value corresponds with an underlying placeholder
+// string displayed by a ClipboardHistoryTextItemView. Do not reorder entries,
+// if you must add to it, add at the end.
+enum class ClipboardHistoryPlaceholderStringType {
+  kBitmap = 0,
+  kHtml = 1,
+  kRtf = 2,
+  kWebSmartPaste = 3,
+  kMaxValue = 3,
+};
+
 // Used to draw the UnrenderedHTMLPlaceholderImage, which is shown while HTML is
 // rendering. Drawn in order to turn the square and single colored SVG into a
 // multicolored rectangle image.
@@ -108,6 +120,11 @@ base::string16 GetLabelForCustomData(const ui::ClipboardData& data) {
       base::UnescapeRule::SPACES));
 }
 
+void RecordPlaceholderString(ClipboardHistoryPlaceholderStringType type) {
+  base::UmaHistogramEnumeration(
+      "Ash.ClipboardHistory.ContextMenu.ShowPlaceholderString", type);
+}
+
 }  // namespace
 
 // ClipboardHistoryResourceManager ---------------------------------------------
@@ -143,6 +160,7 @@ base::string16 ClipboardHistoryResourceManager::GetLabel(
   const ui::ClipboardData& data = item.data();
   switch (ClipboardHistoryUtil::CalculateMainFormat(data).value()) {
     case ui::ClipboardInternalFormat::kBitmap:
+      RecordPlaceholderString(ClipboardHistoryPlaceholderStringType::kBitmap);
       return GetLocalizedString(IDS_CLIPBOARD_MENU_IMAGE);
     case ui::ClipboardInternalFormat::kText:
       return base::UTF8ToUTF16(data.text());
@@ -150,14 +168,18 @@ base::string16 ClipboardHistoryResourceManager::GetLabel(
       // Show plain-text if it exists, otherwise show the placeholder.
       if (!data.text().empty())
         return base::UTF8ToUTF16(data.text());
+      RecordPlaceholderString(ClipboardHistoryPlaceholderStringType::kHtml);
       return GetLocalizedString(IDS_CLIPBOARD_MENU_HTML);
     case ui::ClipboardInternalFormat::kSvg:
       return base::UTF8ToUTF16(data.svg_data());
     case ui::ClipboardInternalFormat::kRtf:
+      RecordPlaceholderString(ClipboardHistoryPlaceholderStringType::kRtf);
       return GetLocalizedString(IDS_CLIPBOARD_MENU_RTF_CONTENT);
     case ui::ClipboardInternalFormat::kBookmark:
       return base::UTF8ToUTF16(data.bookmark_title());
     case ui::ClipboardInternalFormat::kWeb:
+      RecordPlaceholderString(
+          ClipboardHistoryPlaceholderStringType::kWebSmartPaste);
       return GetLocalizedString(IDS_CLIPBOARD_MENU_WEB_SMART_PASTE);
     case ui::ClipboardInternalFormat::kCustom:
       return GetLabelForCustomData(data);

tools/metrics/histograms/enums.xml

@@ -11334,6 +11334,13 @@ histogram as enum -->
   <int value="2" label="Html"/>
 </enum>
 
+<enum name="ClipboardHistoryPlaceholderStringType">
+  <int value="0" label="Bitmap"/>
+  <int value="1" label="Html"/>
+  <int value="2" label="Rtf"/>
+  <int value="3" label="Web Smart Paste"/>
+</enum>
+
 <enum name="ClockdriftLevel">
   <int value="0" label="None"/>
   <int value="1" label="Probable"/>

tools/metrics/histograms/histograms_xml/ash/histograms.xml

@@ -387,6 +387,17 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
+<histogram name="Ash.ClipboardHistory.ContextMenu.ShowPlaceholderString"
+    enum="ClipboardHistoryPlaceholderStringType" expires_after="2021-09-01">
+  <owner>newcomer@chromium.org</owner>
+  <owner>multipaste@google.com</owner>
+  <summary>
+    The number of placeholder strings shown to users in lieu of actual data,
+    broken down by placeholder string type. Recorded when the label is requested
+    from ClipboardHistoryResourceManager.
+  </summary>
+</histogram>
+
 <histogram name="Ash.ClipboardHistory.ContextMenu.UserJourneyTime" units="ms"
     expires_after="2021-09-01">
   <owner>andrewxu@chromium.org</owner>