[Web Payments] Initial plumb of Payment Request dialog

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 19f94c6d392b27014d05468bd0366373e0207029..1340a4f3081b27062d51a7406a31cbfc41421457 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -57,6 +57,7 @@
 #include "chrome/browser/notifications/platform_notification_service_impl.h"
 #include "chrome/browser/page_load_metrics/metrics_navigation_throttle.h"
 #include "chrome/browser/password_manager/chrome_password_manager_client.h"
+#include "chrome/browser/payments/payment_request_impl.h"
 #include "chrome/browser/permissions/permission_context_base.h"
 #include "chrome/browser/platform_util.h"
 #include "chrome/browser/prerender/prerender_final_status.h"
@@ -1405,6 +1406,15 @@ bool IsAutoReloadVisibleOnlyEnabled() {
   return true;
 }
 
+#if defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(OS_WIN)
+bool AreExperimentalWebPlatformFeaturesEnabled() {
+  const base::CommandLine& browser_command_line =
+      *base::CommandLine::ForCurrentProcess();
+  return browser_command_line.HasSwitch(
+      switches::kEnableExperimentalWebPlatformFeatures);
+}
+#endif
+
 void MaybeAppendBlinkSettingsSwitchForFieldTrial(
     const base::CommandLine& browser_command_line,
     base::CommandLine* command_line) {
@@ -2976,7 +2986,16 @@ void ChromeContentBrowserClient::RegisterRenderFrameMojoInterfaces(
                    web_contents->GetJavaInterfaces()->GetWeakPtr()));
   }
 #endif
-
+#if defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(OS_WIN)
+  if (AreExperimentalWebPlatformFeaturesEnabled()) {

[please use gerrit instead, 2016/11/04 21:58:12]

nit: I think there's no need to explicitly check the flag. If the flag is
disabled, then this handler will never be invoked. I guess you could argue that
we shave off some memory and startup time by checking for the flag. Not sure
what you reasoning was. Either way, this one is up to you to decide.

[Kevin Bailey, 2016/11/09 16:25:20]

Mostly I was unsure about how reachable this service was, and didn't want it
listening if unneeded. This change is supposed to be invisible without the flag,
and yes, it shouldn't use up any extra memory if the user didn't request it. In
short, I don't see the harm if conditional, but some harm if not.

+    content::WebContents* web_contents =
+        content::WebContents::FromRenderFrameHost(render_frame_host);
+    if (web_contents) {
+      registry->AddInterface(base::Bind(CreatePaymentRequestHandler,
+          render_frame_host, web_contents));
+    }
+  }
+#endif
 #if defined(ENABLE_MEDIA_ROUTER)
   registry->AddInterface(
       base::Bind(&CastRemotingConnector::CreateRemoterFactory,