--- a/editor/libeditor/HTMLAbsPositionEditor.cpp
+++ b/editor/libeditor/HTMLAbsPositionEditor.cpp
@@ -301,16 +301,18 @@ HTMLEditor::ShowGrabber(Element& aElemen
   nsIContent* parentContent = aElement.GetParent();
   if (NS_WARN_IF(!parentContent)) {
     return NS_ERROR_FAILURE;
   }
 
   mGrabber = CreateGrabber(*parentContent);
   NS_ENSURE_TRUE(mGrabber, NS_ERROR_FAILURE);
 
+  mHasShownGrabber = true;
+
   // and set its position
   return RefreshGrabber();
 }
 
 nsresult
 HTMLEditor::StartMoving()
 {
   nsCOMPtr<nsIContent> parentContent = mGrabber->GetParent();

--- a/editor/libeditor/HTMLEditor.cpp
+++ b/editor/libeditor/HTMLEditor.cpp
@@ -6,16 +6,17 @@
 #include "mozilla/HTMLEditor.h"
 
 #include "mozilla/ComposerCommandsUpdater.h"
 #include "mozilla/DebugOnly.h"
 #include "mozilla/EditAction.h"
 #include "mozilla/EditorDOMPoint.h"
 #include "mozilla/EventStates.h"
 #include "mozilla/mozInlineSpellChecker.h"
+#include "mozilla/Telemetry.h"
 #include "mozilla/TextEvents.h"
 
 #include "nsCRT.h"
 
 #include "nsUnicharUtils.h"
 
 #include "HTMLEditorEventListener.h"
 #include "HTMLEditRules.h"
@@ -98,40 +99,46 @@ HTMLEditor::InsertNodeIntoProperAncestor
               nsIContent& aNode,
               const EditorRawDOMPoint& aPointToInsert,
               SplitAtEdges aSplitAtEdges);
 
 HTMLEditor::HTMLEditor()
   : mCRInParagraphCreatesParagraph(false)
   , mCSSAware(false)
   , mSelectedCellIndex(0)
+  , mHasShownResizers(false)
   , mIsObjectResizingEnabled(true)
   , mIsResizing(false)
   , mPreserveRatio(false)
   , mResizedObjectIsAnImage(false)
   , mIsAbsolutelyPositioningEnabled(true)
   , mResizedObjectIsAbsolutelyPositioned(false)
+  , mHasShownGrabber(false)
   , mGrabberClicked(false)
   , mIsMoving(false)
   , mSnapToGridEnabled(false)
+  , mHasShownInlineTableEditor(false)
   , mIsInlineTableEditingEnabled(true)
   , mOriginalX(0)
   , mOriginalY(0)
   , mResizedObjectX(0)
   , mResizedObjectY(0)
   , mResizedObjectWidth(0)
   , mResizedObjectHeight(0)
   , mResizedObjectMarginLeft(0)
   , mResizedObjectMarginTop(0)
   , mResizedObjectBorderLeft(0)
   , mResizedObjectBorderTop(0)
   , mXIncrementFactor(0)
   , mYIncrementFactor(0)
   , mWidthIncrementFactor(0)
   , mHeightIncrementFactor(0)
+  , mResizerUsedCount(0)
+  , mGrabberUsedCount(0)
+  , mInlineTableEditorUsedCount(0)
   , mInfoXIncrement(20)
   , mInfoYIncrement(20)
   , mPositionedObjectX(0)
   , mPositionedObjectY(0)
   , mPositionedObjectWidth(0)
   , mPositionedObjectHeight(0)
   , mPositionedObjectMarginLeft(0)
   , mPositionedObjectMarginTop(0)
@@ -159,16 +166,41 @@ HTMLEditor::~HTMLEditor()
     if (ps && ps->GetPresContext()) {
       ps->GetPresContext()->SetLinkHandler(mLinkHandler);
     }
   }
 
   RemoveEventListeners();
 
   HideAnonymousEditingUIs();
+
+  Telemetry::Accumulate(
+    Telemetry::HTMLEDITORS_WITH_RESIZERS,
+    mHasShownResizers ? 1 : 0);
+  if (mHasShownResizers) {
+    Telemetry::Accumulate(
+      Telemetry::HTMLEDITORS_WHOSE_RESIZERS_USED_BY_USER,
+      mResizerUsedCount);
+  }
+  Telemetry::Accumulate(
+    Telemetry::HTMLEDITORS_WITH_ABSOLUTE_POSITIONER,
+    mHasShownGrabber ? 1 : 0);
+  if (mHasShownGrabber) {
+    Telemetry::Accumulate(
+      Telemetry::HTMLEDITORS_WHOSE_ABSOLUTE_POSITIONER_USED_BY_USER,
+      mGrabberUsedCount);
+  }
+  Telemetry::Accumulate(
+    Telemetry::HTMLEDITORS_WITH_INLINE_TABLE_EDITOR,
+    mHasShownInlineTableEditor ? 1 : 0);
+  if (mHasShownInlineTableEditor) {
+    Telemetry::Accumulate(
+      Telemetry::HTMLEDITORS_WHOSE_INLINE_TABLE_EDITOR_USED_BY_USER,
+      mInlineTableEditorUsedCount);
+  }
 }
 
 void
 HTMLEditor::HideAnonymousEditingUIs()
 {
   if (mAbsolutelyPositionedObject) {
     HideGrabber();
   }

--- a/editor/libeditor/HTMLEditor.h
+++ b/editor/libeditor/HTMLEditor.h
@@ -1284,31 +1284,39 @@ protected:
                                     int32_t& aMarginLeft,
                                     int32_t& aMarginTop);
 
   bool IsInObservedSubtree(nsIContent* aChild);
 
   void UpdateRootElement();
 
   // resizing
+  // If the instance has shown resizers at least once, mHasShownResizers is
+  // set to true.
+  bool mHasShownResizers;
   bool mIsObjectResizingEnabled;
   bool mIsResizing;
   bool mPreserveRatio;
   bool mResizedObjectIsAnImage;
 
   // absolute positioning
   bool mIsAbsolutelyPositioningEnabled;
   bool mResizedObjectIsAbsolutelyPositioned;
-
+  // If the instance has shown grabber at least once, mHasShownGrabber is
+  // set to true.
+  bool mHasShownGrabber;
   bool mGrabberClicked;
   bool mIsMoving;
 
   bool mSnapToGridEnabled;
 
   // inline table editing
+  // If the instance has shown inline table editor at least once,
+  // mHasShownInlineTableEditor is set to true.
+  bool mHasShownInlineTableEditor;
   bool mIsInlineTableEditingEnabled;
 
   // resizing
   ManualNACPtr mTopLeftHandle;
   ManualNACPtr mTopHandle;
   ManualNACPtr mTopRightHandle;
   ManualNACPtr mLeftHandle;
   ManualNACPtr mRightHandle;
@@ -1339,16 +1347,22 @@ protected:
   int32_t mResizedObjectBorderLeft;
   int32_t mResizedObjectBorderTop;
 
   int32_t mXIncrementFactor;
   int32_t mYIncrementFactor;
   int32_t mWidthIncrementFactor;
   int32_t mHeightIncrementFactor;
 
+  // When resizers, grabber and/or inline table editor are operated by user
+  // actually, the following counters are increased.
+  uint32_t mResizerUsedCount;
+  uint32_t mGrabberUsedCount;
+  uint32_t mInlineTableEditorUsedCount;
+
   int8_t  mInfoXIncrement;
   int8_t  mInfoYIncrement;
 
   nsresult SetAllResizersPosition();
 
   /**
    * Shows active resizers around an element's frame
    * @param aResizedElement [IN] a DOM Element

--- a/editor/libeditor/HTMLEditorObjectResizer.cpp
+++ b/editor/libeditor/HTMLEditorObjectResizer.cpp
@@ -352,16 +352,18 @@ HTMLEditor::ShowResizersInner(Element& a
   }
   // XXX Even when it failed to add event listener, should we need to set
   //     _moz_resizing attribute?
   aResizedElement.SetAttr(kNameSpaceID_None, nsGkAtoms::_moz_resizing,
                           NS_LITERAL_STRING("true"), true);
 
   MOZ_ASSERT(mResizedObject == &aResizedElement);
 
+  mHasShownResizers = true;
+
   return NS_OK;
 }
 
 NS_IMETHODIMP
 HTMLEditor::HideResizers()
 {
   NS_ENSURE_TRUE(mResizedObject, NS_OK);
 
@@ -528,25 +530,26 @@ HTMLEditor::OnMouseDown(int32_t aClientX
 
   nsAutoString anonclass;
   element->GetAttribute(NS_LITERAL_STRING("_moz_anonclass"), anonclass);
 
   if (anonclass.EqualsLiteral("mozResizer")) {
     // If we have an anonymous element and that element is a resizer,
     // let's start resizing!
     aEvent->PreventDefault();
-
+    mResizerUsedCount++;
     mOriginalX = aClientX;
     mOriginalY = aClientY;
     return StartResizing(aTarget);
   }
 
   if (anonclass.EqualsLiteral("mozGrabber")) {
     // If we have an anonymous element and that element is a grabber,
     // let's start moving the element!
+    mGrabberUsedCount++;
     mOriginalX = aClientX;
     mOriginalY = aClientY;
     return GrabberClicked();
   }
 
   return NS_OK;
 }
 

--- a/editor/libeditor/HTMLInlineTableEditor.cpp
+++ b/editor/libeditor/HTMLInlineTableEditor.cpp
@@ -83,16 +83,19 @@ HTMLEditor::ShowInlineTableEditingUI(Ele
   AddMouseClickListener(mAddColumnBeforeButton);
   AddMouseClickListener(mRemoveColumnButton);
   AddMouseClickListener(mAddColumnAfterButton);
   AddMouseClickListener(mAddRowBeforeButton);
   AddMouseClickListener(mRemoveRowButton);
   AddMouseClickListener(mAddRowAfterButton);
 
   mInlineEditedCell = aCell;
+
+  mHasShownInlineTableEditor = true;
+
   return RefreshInlineTableEditingUI();
 }
 
 nsresult
 HTMLEditor::HideInlineTableEditingUI()
 {
   mInlineEditedCell = nullptr;
 
@@ -154,16 +157,18 @@ HTMLEditor::DoInlineTableEditingAction(c
     DeleteTableRow(1);
 #ifndef DISABLE_TABLE_DELETION
     hideUI = (rowCount == 1);
 #endif
   } else {
     return NS_OK;
   }
 
+  ++mInlineTableEditorUsedCount;
+
   // InsertTableRow might causes reframe
   if (Destroyed()) {
     return NS_OK;
   }
 
   if (hideUI) {
     HideInlineTableEditingUI();
     if (hideResizersWithInlineTableUI) {

--- a/toolkit/components/telemetry/Histograms.json
+++ b/toolkit/components/telemetry/Histograms.json
@@ -13804,10 +13804,70 @@
   "PERMISSION_REQUEST_HANDLING_USER_INPUT": {
     "record_in_processes": ["main"],
     "alert_emails": ["jhofmann@mozilla.com"],
     "bug_numbers": [1286118],
     "expires_in_version": "64",
     "kind": "boolean",
     "keyed": true,
     "description": "Permission requests (showing a permission prompt) by whether they were requested from code handling a user input event."
+  },
+  "HTMLEDITORS_WITH_RESIZERS": {
+    "record_in_processes": ["content"],
+    "alert_emails": ["mnakano@mozilla.com"],
+    "bug_numbers": [1452538,1449564],
+    "expires_in_version": "65",
+    "kind": "boolean",
+    "releaseChannelCollection": "opt-out",
+    "description": "Number of HTML editors which has shown object resizers."
+  },
+  "HTMLEDITORS_WHOSE_RESIZERS_USED_BY_USER": {
+    "record_in_processes": ["content"],
+    "alert_emails": ["mnakano@mozilla.com"],
+    "bug_numbers": [1452538,1449564],
+    "expires_in_version": "65",
+    "kind": "linear",
+    "high": 50,
+    "n_buckets": 20,
+    "releaseChannelCollection": "opt-out",
+    "description": "Number of HTML editors whose object resizers are actually used by users."
+  },
+  "HTMLEDITORS_WITH_ABSOLUTE_POSITIONER": {
+    "record_in_processes": ["content"],
+    "alert_emails": ["mnakano@mozilla.com"],
+    "bug_numbers": [1452538,1449564],
+    "expires_in_version": "65",
+    "kind": "boolean",
+    "releaseChannelCollection": "opt-out",
+    "description": "Number of HTML editors which has shown grabber to move absolute positioned elements."
+  },
+  "HTMLEDITORS_WHOSE_ABSOLUTE_POSITIONER_USED_BY_USER": {
+    "record_in_processes": ["content"],
+    "alert_emails": ["mnakano@mozilla.com"],
+    "bug_numbers": [1452538,1449564],
+    "expires_in_version": "65",
+    "kind": "linear",
+    "high": 50,
+    "n_buckets": 20,
+    "releaseChannelCollection": "opt-out",
+    "description": "Number of HTML editors whose grabber to move absolute positioned elements is actually used by users."
+  },
+  "HTMLEDITORS_WITH_INLINE_TABLE_EDITOR": {
+    "record_in_processes": ["content"],
+    "alert_emails": ["mnakano@mozilla.com"],
+    "bug_numbers": [1452538,1449564],
+    "expires_in_version": "65",
+    "kind": "boolean",
+    "releaseChannelCollection": "opt-out",
+    "description": "Number of HTML editors which has shown inline table editing UI."
+  },
+  "HTMLEDITORS_WHOSE_INLINE_TABLE_EDITOR_USED_BY_USER": {
+    "record_in_processes": ["content"],
+    "alert_emails": ["mnakano@mozilla.com"],
+    "bug_numbers": [1452538,1449564],
+    "expires_in_version": "65",
+    "kind": "linear",
+    "high": 50,
+    "n_buckets": 20,
+    "releaseChannelCollection": "opt-out",
+    "description": "Number of HTML editors whose inline table editing UI is actually used by users."
   }
 }