Remove width and height property from <webview> tag.

chrome/renderer/resources/extensions/browser_tag.js

Index: chrome/renderer/resources/extensions/browser_tag.js
diff --git a/chrome/renderer/resources/extensions/browser_tag.js b/chrome/renderer/resources/extensions/browser_tag.js
index f72af00f94073030660d61a78dab400bd42dbf74..2d31d11ee59b7e29bc9d6a4208e0313feea3c8b5 100644
--- a/chrome/renderer/resources/extensions/browser_tag.js
+++ b/chrome/renderer/resources/extensions/browser_tag.js
@@ -7,7 +7,7 @@
 // The actual tag is implemented via the browser plugin. The internals of this
 // are hidden via Shadow DOM.
 
-var BROWSER_TAG_ATTRIBUTES = ['src', 'width', 'height'];
+var BROWSER_TAG_ATTRIBUTES = ['src'];
 
 var BROWSER_TAG_READONLY_ATTRIBUTES = ['contentWindow'];
 
@@ -56,6 +56,9 @@ function BrowserTag(node) {
 
   this.objectNode_ = document.createElement('object');
   this.objectNode_.type = 'application/browser-plugin';
+  // The <object> node fills in the <browser> container.
+  this.objectNode_.style.width = '100%';
+  this.objectNode_.style.height = '100%';
   BROWSER_TAG_ATTRIBUTES.forEach(this.copyAttribute_, this);
 
   shadowRoot.appendChild(this.objectNode_);