[DevTools] Remove Common.Event.target field.

third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js

Index: third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js b/third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
index 770c9505f3e35f3363db9704b214e30fe7f3b709..d6ecba643d25b13b6fd1dae65766a5c713d9bb6c 100644
--- a/third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
+++ b/third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js
@@ -284,6 +284,9 @@ Sources.JavaScriptSourceFrame = class extends Sources.UISourceCodeFrame {
         .then(populateSourceMapMembers.bind(this));
   }
 
+  /**
+   * @param {!Common.Event} event
+   */
   _workingCopyChanged(event) {
     if (this._supportsEnabledBreakpointsWhileEditing() || this._scriptFileForTarget.size)
       return;
@@ -294,6 +297,9 @@ Sources.JavaScriptSourceFrame = class extends Sources.UISourceCodeFrame {
       this._restoreBreakpointsAfterEditing();
   }
 
+  /**
+   * @param {!Common.Event} event
+   */
   _workingCopyCommitted(event) {
     this._scriptsPanel.updateLastModificationTime();
     if (this._supportsEnabledBreakpointsWhileEditing())