[DevTools] Handle emulation in embedder, call into web API.

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index 0a8ce9b6810f12a908f87072da12acc1746e1f7c..2fe14173e171dc30ea9465a0e3715beb4651ab97 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -3633,14 +3633,13 @@ void RenderViewImpl::DidCompletePageScaleAnimation() {
 }
 
 void RenderViewImpl::SetScreenMetricsEmulationParameters(
-    float device_scale_factor,
-    const gfx::Point& root_layer_offset,
-    float root_layer_scale) {
+    bool enabled,
+    const blink::WebDeviceEmulationParams& params) {
   if (webview() && compositor()) {
-    webview()->setCompositorDeviceScaleFactorOverride(device_scale_factor);
-    webview()->setRootLayerTransform(
-        blink::WebSize(root_layer_offset.x(), root_layer_offset.y()),
-        root_layer_scale);
+    if (enabled)
+      webview()->enableDeviceEmulation(params);
+    else
+      webview()->disableDeviceEmulation();
   }
 }