[Contextual Search] Add Mojo-enabled API component.

chrome/renderer/chrome_content_renderer_client.cc

Index: chrome/renderer/chrome_content_renderer_client.cc
diff --git a/chrome/renderer/chrome_content_renderer_client.cc b/chrome/renderer/chrome_content_renderer_client.cc
index 1a2aebdc773dabb5fd39ae0531f76a41d1624ca4..5d05399f3b9136a7a82fb008ff23be1c3f9e175c 100644
--- a/chrome/renderer/chrome_content_renderer_client.cc
+++ b/chrome/renderer/chrome_content_renderer_client.cc
@@ -34,6 +34,7 @@
 #include "chrome/renderer/chrome_render_process_observer.h"
 #include "chrome/renderer/chrome_render_view_observer.h"
 #include "chrome/renderer/content_settings_observer.h"
+#include "chrome/renderer/contextualsearch/contextual_search_wrapper.h"
 #include "chrome/renderer/external_extension.h"
 #include "chrome/renderer/loadtimes_extension_bindings.h"
 #include "chrome/renderer/media/chrome_key_systems.h"
@@ -558,6 +559,12 @@ void ChromeContentRendererClient::RenderFrameCreated(
     // Only attach MainRenderFrameObserver to the main frame, since
     // we only want to log page load metrics for the main frame.
     new page_load_metrics::MetricsRenderFrameObserver(render_frame);
+
+    // Install Contextual Search support in the main frame if needed.
+    if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+            switches::kContextualSearchProcess)) {
+      search::ContextualSearchWrapper::Install(render_frame->GetWebFrame());
+    }
   } else {
     // Avoid any race conditions from having the browser tell subframes that
     // they're prerendering.