(NOT FOR COMMIT) Testing layer invalidation speedups.

cc/blink/web_layer_impl.cc

Index: cc/blink/web_layer_impl.cc
diff --git a/cc/blink/web_layer_impl.cc b/cc/blink/web_layer_impl.cc
index abb6e501137ba8a88c69e4d0e0657416f571ed4a..a80dfab41effea7f92ea6b1c6fb20b2c69890dfb 100644
--- a/cc/blink/web_layer_impl.cc
+++ b/cc/blink/web_layer_impl.cc
@@ -58,6 +58,12 @@ void WebLayerImpl::invalidateRect(const blink::WebRect& rect) {
   layer_->SetNeedsDisplayRect(rect);
 }
 
+void WebLayerImpl::invalidateRects(const std::vector<blink::WebRect>& rects) {
+  for (size_t i = 0; i < rects.size(); ++i) {
+    layer_->SetNeedsDisplayRect(rects[i]);
+  }
+}
+
 void WebLayerImpl::invalidate() {
   layer_->SetNeedsDisplay();
 }