Plugin Power Saver: Implement srcset syntax for posters.

chrome/renderer/plugins/chrome_plugin_placeholder.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/plugins/chrome_plugin_placeholder.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/common/prerender_messages.h"
 #include "chrome/common/render_messages.h"
@@ skipping 38 matching lines @@
 // The placeholder is loaded in normal web renderer processes, so it should not
 // have a chrome:// scheme that might let it be confused with a WebUI page.
 const char ChromePluginPlaceholder::kPluginPlaceholderDataURL[] =
     "data:text/html,pluginplaceholderdata";
 
 ChromePluginPlaceholder::ChromePluginPlaceholder(
     content::RenderFrame* render_frame,
     blink::WebLocalFrame* frame,
     const blink::WebPluginParams& params,
     const std::string& html_data,
-    const base::string16& title)
+    const base::string16& title,
+    const GURL& placeholder_url)
     : plugins::LoadablePluginPlaceholder(render_frame,
                                          frame,
                                          params,
                                          html_data,
-                                         GURL(kPluginPlaceholderDataURL)),
+                                         placeholder_url),
       status_(new ChromeViewHostMsg_GetPluginInfo_Status),
       title_(title),
 #if defined(ENABLE_PLUGIN_INSTALLATION)
       placeholder_routing_id_(MSG_ROUTING_NONE),
 #endif
       has_host_(false),
       context_menu_request_id_(0) {
   RenderThread::Get()->AddObserver(this);
 }
 
@@ skipping 27 matching lines @@
   values.SetString("message", l10n_util::GetStringUTF8(IDS_PLUGIN_SEARCHING));
 #else
   values.SetString("message",
                    l10n_util::GetStringUTF8(IDS_PLUGIN_NOT_SUPPORTED));
 #endif
 
   std::string html_data = webui::GetI18nTemplateHtml(template_html, &values);
 
   // |missing_plugin| will destroy itself when its WebViewPlugin is going away.
   ChromePluginPlaceholder* missing_plugin = new ChromePluginPlaceholder(
-      render_frame, frame, params, html_data, params.mimeType);
+      render_frame, frame, params, html_data, params.mimeType,
+      GURL(kPluginPlaceholderDataURL));
   missing_plugin->set_allow_loading(true);
 #if defined(ENABLE_PLUGIN_INSTALLATION)
   RenderThread::Get()->Send(
       new ChromeViewHostMsg_FindMissingPlugin(missing_plugin->routing_id(),
                                               missing_plugin->CreateRoutingId(),
                                               params.mimeType.utf8()));
 #endif
   return missing_plugin;
 }
 
 // static
 ChromePluginPlaceholder* ChromePluginPlaceholder::CreateErrorPlugin(
     content::RenderFrame* render_frame,
     const base::FilePath& file_path) {
   base::DictionaryValue values;
   values.SetString("message",
                    l10n_util::GetStringUTF8(IDS_PLUGIN_INITIALIZATION_ERROR));
 
   const base::StringPiece template_html(
       ResourceBundle::GetSharedInstance().GetRawDataResource(
           IDR_BLOCKED_PLUGIN_HTML));
   std::string html_data = webui::GetI18nTemplateHtml(template_html, &values);
 
   WebPluginParams params;
   // |missing_plugin| will destroy itself when its WebViewPlugin is going away.
   ChromePluginPlaceholder* plugin = new ChromePluginPlaceholder(
-      render_frame, NULL, params, html_data, params.mimeType);
+      render_frame, NULL, params, html_data, params.mimeType,
+      GURL(kPluginPlaceholderDataURL));
 
   RenderThread::Get()->Send(new ChromeViewHostMsg_CouldNotLoadPlugin(
       plugin->routing_id(), file_path));
   return plugin;
 }
 
 // static
 ChromePluginPlaceholder* ChromePluginPlaceholder::CreateBlockedPlugin(
     content::RenderFrame* render_frame,
     WebLocalFrame* frame,
     const WebPluginParams& params,
     const content::WebPluginInfo& info,
     const std::string& identifier,
     const base::string16& name,
     int template_id,
     const base::string16& message,
-    const GURL& poster_url) {
+    const std::string& poster_attribute,
+    const GURL& placeholder_url) {
   base::DictionaryValue values;
   values.SetString("message", message);
   values.SetString("name", name);
   values.SetString("hide", l10n_util::GetStringUTF8(IDS_PLUGIN_HIDE));
 
-  if (poster_url.is_valid())
-    values.SetString("background", "url('" + poster_url.spec() + "')");
+  if (!poster_attribute.empty())
+    values.SetString("poster", poster_attribute);
 
   const base::StringPiece template_html(
       ResourceBundle::GetSharedInstance().GetRawDataResource(template_id));
 
   DCHECK(!template_html.empty()) << "unable to load template. ID: "
                                  << template_id;
   std::string html_data = webui::GetI18nTemplateHtml(template_html, &values);
 
   // |blocked_plugin| will destroy itself when its WebViewPlugin is going away.
   ChromePluginPlaceholder* blocked_plugin = new ChromePluginPlaceholder(
-      render_frame, frame, params, html_data, name);
+      render_frame, frame, params, html_data, name,
+      placeholder_url.is_valid() ? placeholder_url

[tommycli, 2015/03/04 19:55:17]

Needs some security scrutiny:

In order to allow resolving of relative paths, we set the placeholder's URL to
the document URL instead of data:text/html,pluginplaceholderdata.

Is this safe? I could not think of another reasonable alternative to doing this.

Previously, we resolved the image to an absolute path before passing it into
here. Now, we are switching to the img srcset syntax, i.e. <img
srcset="poster1x.png 1x, poster2x.png 2x">.

The srcset parsing code is deep and nonpublic in Blink, so it would be a real
PITA to resolve them to absolute paths.

[Bernhard Bauer, 2015/03/05 09:12:51]

Could you just set a <base> tag in the header? That would allow resolving
relative URLs, without changing security-related properties (AFAIK).

[tommycli, 2015/03/05 19:49:12]

That totally worked! You guys are smarter than me!

+                                 : GURL(kPluginPlaceholderDataURL));
 
 #if defined(ENABLE_PLUGINS)
-  if (poster_url.is_valid())
+  if (!poster_attribute.empty())
     blocked_plugin->BlockForPowerSaverPoster();
 #endif
   blocked_plugin->SetPluginInfo(info);
   blocked_plugin->SetIdentifier(identifier);
   return blocked_plugin;
 }
 
 void ChromePluginPlaceholder::SetStatus(
     const ChromeViewHostMsg_GetPluginInfo_Status& status) {
   status_->value = status.value;
@@ skipping 186 matching lines @@
   v8::Handle<v8::Object> global = context->Global();
   global->Set(gin::StringToV8(isolate, "plugin"),
               gin::CreateHandle(isolate, this).ToV8());
 }
 
 gin::ObjectTemplateBuilder ChromePluginPlaceholder::GetObjectTemplateBuilder(
     v8::Isolate* isolate) {
   return LoadablePluginPlaceholder::GetObjectTemplateBuilder(isolate).SetMethod(
       "openAboutPlugins", &ChromePluginPlaceholder::OpenAboutPluginsCallback);
 }