Enable shadow DOM-based "missing plugin" placeholder.

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 9f99262d1107d5279a117484abf56333be0263a1..cb819e4d21f22518e46e25123e04ce9dedb71d7b 100644
--- a/chrome/renderer/chrome_content_renderer_client.cc
+++ b/chrome/renderer/chrome_content_renderer_client.cc
@@ -45,6 +45,7 @@
 #include "chrome/renderer/playback_extension.h"
 #include "chrome/renderer/plugins/chrome_plugin_placeholder.h"
 #include "chrome/renderer/plugins/plugin_uma.h"
+#include "chrome/renderer/plugins/shadow_dom_plugin_placeholder.h"
 #include "chrome/renderer/prefetch_helper.h"
 #include "chrome/renderer/prerender/prerender_dispatcher.h"
 #include "chrome/renderer/prerender/prerender_helper.h"
@@ -92,6 +93,7 @@
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "third_party/WebKit/public/web/WebPluginContainer.h"
 #include "third_party/WebKit/public/web/WebPluginParams.h"
+#include "third_party/WebKit/public/web/WebPluginPlaceholder.h"
 #include "third_party/WebKit/public/web/WebSecurityOrigin.h"
 #include "third_party/WebKit/public/web/WebSecurityPolicy.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -547,6 +549,41 @@ const Extension* ChromeContentRendererClient::GetExtensionByOrigin(
 }
 #endif
 
+blink::WebPluginPlaceholder*
+ChromeContentRendererClient::OverrideCreatePluginPlaceholder(
+    content::RenderFrame* render_frame,
+    blink::WebLocalFrame* frame,
+    const blink::WebPluginParams& orig_params) {
+  using Status = ChromeViewHostMsg_GetPluginInfo_Status;
+
+  if (!ShadowDOMPluginPlaceholderEnabled())
+    return nullptr;
+
+  std::string orig_mime_type = orig_params.mimeType.utf8();
+  // TODO(jbroman): Investigate whether browser plugin needs special handling.
+  ChromeViewHostMsg_GetPluginInfo_Output output;
+#if defined(ENABLE_PLUGINS)
+  render_frame->Send(
+      new ChromeViewHostMsg_GetPluginInfo(render_frame->GetRoutingID(),
+                                          GURL(orig_params.url),
+                                          frame->top()->document().url(),
+                                          orig_mime_type,
+                                          &output));
+#else
+  output.status.value = Status::kNotFound;
+#endif
+
+  Status::Value status = output.status.value;
+  if (status == Status::kNotFound) {
+    // TODO(jbroman): Handle YouTube specially here, as in CreatePlugin.
+    PluginUMAReporter::GetInstance()->ReportPluginMissing(orig_mime_type,
+                                                          orig_params.url);
+    return CreateShadowDOMPlaceholderForMissingPlugin().release();

[Bernhard Bauer, 2014/10/29 09:53:05]

Urr... if this method passes ownership of its return value anyway, why don't we
make it return a scoped_ptr straight away?

[jbroman, 2014/10/29 17:14:43]

It wasn't clear to me when it should be released from scoped_ptr. Certainly
scoped_ptr doesn't exist in Blink, so it has to be a WebPluginPlaceholder* when
it crosses that boundary. It seemed to me that the convention for in the
content/public/ was to return raw pointers, but I wasn't sure.

It also necessitates completing the definition of blink::WebPluginPlaceholder
for ~scoped_ptr to compile, but such is life.

(as an aside, though, not using smart pointers here has already caused me to
leak memory in my tests -- evidence that they are a good idea)

I'll make it scoped_ptr here and unwrap it in content::RenderFrameImpl, then,
okay? (On the Blink side, it's quickly wrapped in an OwnPtr again.)

+  }
+
+  return nullptr;
+}
+
 bool ChromeContentRendererClient::OverrideCreatePlugin(
     content::RenderFrame* render_frame,
     WebLocalFrame* frame,