Revert of [DevTools] Remove methods on Common.Event.

third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js

Index: third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js b/third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js
index 1fccd2fb4838e472e53d6c43d449d2ed9f95cc9f..7312c980c7ab6079828771caea67357f30162114 100644
--- a/third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js
+++ b/third_party/WebKit/Source/devtools/front_end/sdk/DebuggerModel.js
@@ -411,8 +411,8 @@
     this._isPausing = false;
     this._debuggerPausedDetails = debuggerPausedDetails;
     if (this._debuggerPausedDetails) {
-      if (Runtime.experiments.isEnabled('emptySourceMapAutoStepping') && this._beforePausedCallback) {
-        if (!this._beforePausedCallback.call(null, this._debuggerPausedDetails))
+      if (Runtime.experiments.isEnabled('emptySourceMapAutoStepping')) {
+        if (this.dispatchEventToListeners(SDK.DebuggerModel.Events.BeforeDebuggerPaused, this._debuggerPausedDetails))
           return false;
       }
       this.dispatchEventToListeners(SDK.DebuggerModel.Events.DebuggerPaused, this._debuggerPausedDetails);
@@ -422,13 +422,6 @@
     else
       this.setSelectedCallFrame(null);
     return true;
-  }
-
-  /**
-   * @param {?function(!SDK.DebuggerPausedDetails):boolean} callback
-   */
-  setBeforePausedCallback(callback) {
-    this._beforePausedCallback = callback;
   }
 
   /**
@@ -814,6 +807,7 @@
 SDK.DebuggerModel.Events = {
   DebuggerWasEnabled: Symbol('DebuggerWasEnabled'),
   DebuggerWasDisabled: Symbol('DebuggerWasDisabled'),
+  BeforeDebuggerPaused: Symbol('BeforeDebuggerPaused'),
   DebuggerPaused: Symbol('DebuggerPaused'),
   DebuggerResumed: Symbol('DebuggerResumed'),
   ParsedScriptSource: Symbol('ParsedScriptSource'),