Plugin Power Saver: Restrict Power Saver to cross-origin.

content/renderer/pepper/pepper_plugin_instance_impl.cc

Index: content/renderer/pepper/pepper_plugin_instance_impl.cc
diff --git a/content/renderer/pepper/pepper_plugin_instance_impl.cc b/content/renderer/pepper/pepper_plugin_instance_impl.cc
index 97a85c90f253966dd8e964bd7232cfe7d199e90f..6155dcdbeea54a21cf528474ea83179da4551396 100644
--- a/content/renderer/pepper/pepper_plugin_instance_impl.cc
+++ b/content/renderer/pepper/pepper_plugin_instance_impl.cc
@@ -583,13 +583,9 @@ PepperPluginInstanceImpl::PepperPluginInstanceImpl(
       GetContentClient()->renderer()->IsExternalPepperPlugin(module->name()))
     external_document_load_ = true;
 
-  // TODO(tommycli): Insert heuristics to determine whether plugin content
-  // is peripheral here.
-  bool is_peripheral_content = true;
-  power_saver_enabled_ = is_peripheral_content &&
-      module->name() == kFlashPluginName &&
-      CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kEnablePluginPowerSaver);
+  power_saver_enabled_ = CommandLine::ForCurrentProcess()->HasSwitch(
+                             switches::kEnablePluginPowerSaver) &&
+                         IsPeripheralContent();
 
   if (power_saver_enabled_) {
     throttler_.reset(new PepperPluginInstanceThrottler(
@@ -3299,6 +3295,27 @@ void PepperPluginInstanceImpl::DidDataFromWebURLResponse(
   }
 }
 
+bool PepperPluginInstanceImpl::IsPeripheralContent() const {
+  if (module_->name() != kFlashPluginName)
+    return false;
+
+  // Peripheral plugin content is defined to be peripheral when the plugin
+  // content's origin differs from the top level frame's origin. For example:
+  //  - Peripheral:      a.com -> b.com/plugin.swf
+  //  - Peripheral:      a.com -> b.com/iframe.html -> b.com/plugin.swf
+  //  - NOT peripheral:  a.com -> b.com/iframe-to-a.html -> a.com/plugin.swf
+
+  // TODO(alexmos): Update this to use the origin of the RemoteFrame when 426512
+  // is fixed. For now, case 3 in the comment above doesn't work in
+  // --site-per-process mode.
+  WebFrame* top_frame = render_frame_->GetWebFrame()->view()->mainFrame();

[raymes, 2014/10/23 22:33:19]

nit: might as well call this "main_frame" and "main_frame_url" to match the
language used elsewhere

[tommycli, 2014/10/23 22:42:20]

Done.

+  if (top_frame->isWebRemoteFrame())
+     return true;
+
+  GURL top_frame_url = top_frame->document().url();
+  return plugin_url_.GetOrigin() != top_frame_url.GetOrigin();
+}
+
 void PepperPluginInstanceImpl::SetPluginThrottled(bool throttled) {
   // Do not throttle if we've already disabled power saver.
   if (!power_saver_enabled_ && throttled)