Plugin Power Saver: Make PPS work well with prerendered pages.

content/renderer/pepper/plugin_instance_throttler_impl.cc

Index: content/renderer/pepper/plugin_instance_throttler_impl.cc
diff --git a/content/renderer/pepper/plugin_instance_throttler_impl.cc b/content/renderer/pepper/plugin_instance_throttler_impl.cc
index 593fb99d7fadb924a36c0e4cd68100d9ef121719..5880ed98c292e50a9501fb3c621a38c309fe299d 100644
--- a/content/renderer/pepper/plugin_instance_throttler_impl.cc
+++ b/content/renderer/pepper/plugin_instance_throttler_impl.cc
@@ -9,7 +9,6 @@
 #include "content/public/common/content_constants.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/renderer/pepper/pepper_plugin_instance_impl.h"
-#include "content/renderer/pepper/pepper_webplugin_impl.h"
 #include "content/renderer/render_frame_impl.h"
 #include "ppapi/shared_impl/ppapi_constants.h"
 #include "ppapi/shared_impl/scoped_pp_var.h"
@@ -36,6 +35,37 @@ const int kMinimumConsecutiveInterestingFrames = 4;
 // poster image. Chosen arbitrarily.
 const int kAudioThrottledFrameTimeoutMilliseconds = 500;
 
+class PowerSaverTestPluginDelegate : public PluginInstanceThrottler::Observer {
+ public:
+  explicit PowerSaverTestPluginDelegate(
+      const PluginInstanceThrottlerImpl* throttler)
+      : throttler_(throttler) {}
+
+  virtual ~PowerSaverTestPluginDelegate() {}
+
+ private:
+  void OnThrottleStateChange() override {
+    if (throttler_->GetWebPlugin() && throttler_->GetWebPlugin()->instance()) {
+      throttler_->GetWebPlugin()->instance()->HandleMessage(ppapi::ScopedPPVar(
+          ppapi::ScopedPPVar::PassRef(),
+          ppapi::StringVar::StringToPPVar("throttleStatusChange")));
+    }
+  }
+
+  void OnPeripheralStateChange() override {
+    if (throttler_->GetWebPlugin() && throttler_->GetWebPlugin()->instance()) {
+      throttler_->GetWebPlugin()->instance()->HandleMessage(ppapi::ScopedPPVar(
+          ppapi::ScopedPPVar::PassRef(),
+          ppapi::StringVar::StringToPPVar("peripheralStatusChange")));
+    }
+  }
+
+  void OnThrottlerDestroyed() override { delete this; }
+
+  // Non-owning pointer.
+  const PluginInstanceThrottlerImpl* const throttler_;
+};
+
 }  // namespace
 
 // static
@@ -101,16 +131,10 @@ void PluginInstanceThrottlerImpl::MarkPluginEssential(
   state_ = THROTTLER_STATE_MARKED_ESSENTIAL;
   RecordUnthrottleMethodMetric(method);
 
+  FOR_EACH_OBSERVER(Observer, observer_list_, OnPeripheralStateChange());
+
   if (was_throttled)
     FOR_EACH_OBSERVER(Observer, observer_list_, OnThrottleStateChange());
-
-  // Notify the Power Saver test plugin of a peripheral status change.
-  if (web_plugin_ && web_plugin_->instance() &&
-      plugin_module_name_ == ppapi::kPowerSaverTestPluginName) {
-    web_plugin_->instance()->HandleMessage(ppapi::ScopedPPVar(
-        ppapi::ScopedPPVar::PassRef(),
-        ppapi::StringVar::StringToPPVar("peripheralStatusChange")));
-  }
 }
 
 void PluginInstanceThrottlerImpl::SetHiddenForPlaceholder(bool hidden) {
@@ -118,7 +142,7 @@ void PluginInstanceThrottlerImpl::SetHiddenForPlaceholder(bool hidden) {
   FOR_EACH_OBSERVER(Observer, observer_list_, OnHiddenForPlaceholder(hidden));
 }
 
-blink::WebPlugin* PluginInstanceThrottlerImpl::GetWebPlugin() const {
+PepperWebPluginImpl* PluginInstanceThrottlerImpl::GetWebPlugin() const {
   DCHECK(web_plugin_);
   return web_plugin_;
 }
@@ -143,7 +167,6 @@ void PluginInstanceThrottlerImpl::Initialize(
     const GURL& content_origin,
     const std::string& plugin_module_name,
     const gfx::Size& unobscured_size) {
-  plugin_module_name_ = plugin_module_name;
   unobscured_size_ = unobscured_size;
 
   // |frame| may be nullptr in tests.
@@ -162,6 +185,11 @@ void PluginInstanceThrottlerImpl::Initialize(
       return;
     }
 
+    if (plugin_module_name == ppapi::kPowerSaverTestPluginName) {
+      // Delegate manages its own lifetime.
+      new PowerSaverTestPluginDelegate(this);
+    }
+
     // To collect UMAs, register peripheral content even if power saver mode
     // is disabled.
     helper->RegisterPeripheralPlugin(