Rename webFrame.purgeCaches to webFrame.clearCache

This matches the name of session.clearCache.

docs/api/web-frame.md

@@ -108,47 +108,41 @@ this limitation.
 
 ### `webFrame.getResourceUsage()`
 
-Returns more detailed memory usage information in kilobytes of Blink's internal
-memory caches. Returns an Object of the following shape:
+Returns an object describing usage information of Blink's internal memory
+caches.
 
-```js
+```javascript
+console.log(webFrame.getResourceUsage())
+```
+
+This will generate:
+
+```javascript
 {
-  "images": {
-    "count": 22,
-    "size": 2549,         // 2549kb
-    "liveSize": 2542,     // 2542kb, etc...
-    "decodedSize": 478,
-    "purgedSize": 0,
-    "purgeableSize": 0
+  images: {
+    count: 22,
+    size: 2549,
+    liveSize: 2542,
+    decodedSize: 478,
+    purgedSize: 0,
+    purgeableSize: 0
   },
-  "cssStyleSheets": {
-    "count": 7,
-    /* ... */
-  },
-  "xslStyleSheets": {
-    "count": 0,
-    /* ... */
-  },
-  "fonts": {
-    "count": 18,
-    /* ... */
-  },
-  "other": {
-    "count": 0,
-    /* ... */
-  }
+  cssStyleSheets: { /* same with "images" */ },
+  xslStyleSheets: { /* same with "images" */ },
+  fonts: { /* same with "images" */ },
+  other: { /* same with "images" */ },
 }
 ```
 
-### `webFrame.purgeCaches()`
+### `webFrame.clearCache()`
 
-Attempts to free memory that is no longer being used (i.e. images from a
-previous navigation, etc etc).
+Attempts to free memory that is no longer being used (like images from a
+previous navigation).
 
 Note that blindly calling this method probably makes Electron slower since it
 will have to refill these emptied caches, you should only call it if an event
 in your app has occured that makes you think your page is actually using less
 memory (i.e. you have navigated from a super heavy page to a mostly empty one,
-and intend to stay there)
+and intend to stay there).
 
 [spellchecker]: https://github.com/atom/node-spellchecker