Plugin Power Saver: Add UI Overlay to throttled plugin using placeholder.

content/renderer/pepper/pepper_plugin_instance_impl.cc

 // Copyright (c) 2012 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 "content/renderer/pepper/pepper_plugin_instance_impl.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "base/memory/linked_ptr.h"
@@ skipping 1939 matching lines @@
     return metafile->InitFromData(mapper.data(), mapper.size());
 
   NOTREACHED();
 #endif  // ENABLE_PRINTING
   return false;
 }
 
 void PepperPluginInstanceImpl::UpdateLayer(bool device_changed) {
   if (!container_)
     return;
+  if (throttler_ && throttler_->IsHiddenForPlaceholder())
+    return;
 
   gpu::Mailbox mailbox;
   uint32 sync_point = 0;
   if (bound_graphics_3d_.get()) {
     bound_graphics_3d_->GetBackingMailbox(&mailbox, &sync_point);
     DCHECK_EQ(mailbox.IsZero(), sync_point == 0);
   }
   bool want_3d_layer = !mailbox.IsZero();
   bool want_2d_layer = !!bound_graphics_2d_platform_;
   bool want_texture_layer = want_3d_layer || want_2d_layer;
@@ skipping 66 matching lines @@
   return bound_graphics_2d_platform_->PrepareTextureMailbox(mailbox,
                                                             release_callback);
 }
 
 void PepperPluginInstanceImpl::OnDestruct() { render_frame_ = NULL; }
 
 void PepperPluginInstanceImpl::OnThrottleStateChange() {
   SendDidChangeView();
 }
 
+void PepperPluginInstanceImpl::OnHiddenForPlaceholder(bool hidden) {
+  if (hidden) {
+    container_->setWebLayer(nullptr);
+  } else {
+    UpdateLayer(true /* device_changed */);
+  }
+}
+
 void PepperPluginInstanceImpl::AddLatencyInfo(
     const std::vector<ui::LatencyInfo>& latency_info) {
   if (render_frame_ && render_frame_->GetRenderWidget()) {
     RenderWidgetCompositor* compositor =
         render_frame_->GetRenderWidget()->compositor();
     if (compositor) {
       for (size_t i = 0; i < latency_info.size(); i++) {
         scoped_ptr<cc::SwapPromise> swap_promise(
             new cc::LatencyInfoSwapPromise(latency_info[i]));
         compositor->QueueSwapPromise(swap_promise.Pass());
@@ skipping 1221 matching lines @@
 
 void PepperPluginInstanceImpl::RecordFlashJavaScriptUse() {
   if (!javascript_used_ && is_flash_plugin_) {
     javascript_used_ = true;
     RenderThread::Get()->RecordAction(
         base::UserMetricsAction("Flash.JavaScriptUsed"));
   }
 }
 
 }  // namespace content