DevTools: introduce object previews experiment

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

Index: third_party/WebKit/Source/devtools/front_end/sdk/RemoteObject.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sdk/RemoteObject.js b/third_party/WebKit/Source/devtools/front_end/sdk/RemoteObject.js
index efc30fd9f8e8525818f3029c82a653ca3199ec89..1c9fbef580177fd2dc6c6e396668952ebf3e21cd 100644
--- a/third_party/WebKit/Source/devtools/front_end/sdk/RemoteObject.js
+++ b/third_party/WebKit/Source/devtools/front_end/sdk/RemoteObject.js
@@ -79,6 +79,19 @@ SDK.RemoteObject = class {
   }
 
   /**
+   * @param {!Protocol.Runtime.ObjectPreview} preview
+   * @return {number}
+   */
+  static numEntries(preview) {
+    if (preview.subtype !== 'map' && preview.subtype !== 'set')
+      return 0;
+    var matches = preview.description.match(/\(([0-9]+)\)/);
+    if (!matches)
+      return 0;
+    return parseInt(matches[1], 10);
+  }
+
+  /**
    * @param {!Protocol.Runtime.RemoteObject|!SDK.RemoteObject|number|string|boolean|undefined|null} object
    * @return {!Protocol.Runtime.CallArgument}
    */
@@ -497,7 +510,10 @@ SDK.RemoteObjectImpl = class extends SDK.RemoteObject {
    * @param {function(?Array.<!SDK.RemoteObjectProperty>, ?Array.<!SDK.RemoteObjectProperty>)} callback
    */
   getOwnProperties(callback) {
-    this.doGetProperties(true, false, false, callback);
+    if (Runtime.experiments.isEnabled('objectPreviews'))
+      this.doGetProperties(true, false, true, callback);
+    else
+      this.doGetProperties(true, false, false, callback);
   }
 
   /**
@@ -506,7 +522,10 @@ SDK.RemoteObjectImpl = class extends SDK.RemoteObject {
    * @param {function(?Array.<!SDK.RemoteObjectProperty>, ?Array.<!SDK.RemoteObjectProperty>)} callback
    */
   getAllProperties(accessorPropertiesOnly, callback) {
-    this.doGetProperties(false, accessorPropertiesOnly, false, callback);
+    if (Runtime.experiments.isEnabled('objectPreviews'))
+      this.doGetProperties(false, accessorPropertiesOnly, true, callback);
+    else
+      this.doGetProperties(false, accessorPropertiesOnly, false, callback);
   }
 
   /**