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

content/renderer/devtools/devtools_agent.cc

Index: content/renderer/devtools/devtools_agent.cc
diff --git a/content/renderer/devtools/devtools_agent.cc b/content/renderer/devtools/devtools_agent.cc
index 57f4337919356cecb1d7eba7c24b831f0af23270..5240de5760d66ee1afd80d483a775cd4479a5d70 100644
--- a/content/renderer/devtools/devtools_agent.cc
+++ b/content/renderer/devtools/devtools_agent.cc
@@ -105,6 +105,10 @@ bool DevToolsAgent::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(DevToolsAgentMsg_AddMessageToConsole,
                         OnAddMessageToConsole)
     IPC_MESSAGE_HANDLER(DevToolsMsg_SetupDevToolsClient, OnSetupDevToolsClient)
+    IPC_MESSAGE_HANDLER(DevToolsMsg_EnableDeviceEmulation,
+                        OnEnableDeviceEmulation)
+    IPC_MESSAGE_HANDLER(DevToolsMsg_DisableDeviceEmulation,
+                        OnDisableDeviceEmulation)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -338,6 +342,15 @@ void DevToolsAgent::OnSetupDevToolsClient() {
   new DevToolsClient(main_render_frame_);
 }
 
+void DevToolsAgent::OnEnableDeviceEmulation(
+    const blink::WebDeviceEmulationParams& params) {
+  GetRenderViewImpl()->EnableScreenMetricsEmulation(params);
+}
+
+void DevToolsAgent::OnDisableDeviceEmulation() {
+  GetRenderViewImpl()->DisableScreenMetricsEmulation();
+}
+
 WebDevToolsAgent* DevToolsAgent::GetWebAgent() {
   WebView* web_view = main_render_frame_->GetRenderView()->GetWebView();
   if (!web_view)