Apply artificial memory pressure when backgrounded.

content/renderer/render_thread_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/render_thread_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <vector>
 
 #include "base/allocator/allocator_extension.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
+#include "base/memory/discardable_memory.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/stats_table.h"
 #include "base/path_service.h"
 #include "base/shared_memory.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"  // Temporary
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_local.h"
 #include "base/threading/thread_restrictions.h"
@@ skipping 37 matching lines @@
 #include "content/renderer/media/audio_renderer_mixer_manager.h"
 #include "content/renderer/media/media_stream_center.h"
 #include "content/renderer/media/media_stream_dependency_factory.h"
 #include "content/renderer/media/peer_connection_tracker.h"
 #include "content/renderer/media/video_capture_impl_manager.h"
 #include "content/renderer/media/video_capture_message_filter.h"
 #include "content/renderer/memory_benchmarking_extension.h"
 #include "content/renderer/p2p/socket_dispatcher.h"
 #include "content/renderer/plugin_channel_host.h"
 #include "content/renderer/render_process_impl.h"
+#include "content/renderer/render_process_visibility_manager.h"
 #include "content/renderer/render_view_impl.h"
 #include "content/renderer/renderer_webkitplatformsupport_impl.h"
 #include "content/renderer/skia_benchmarking_extension.h"
 #include "grit/content_resources.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_forwarding_message_filter.h"
 #include "ipc/ipc_platform_file.h"
 #include "media/base/audio_hardware_config.h"
 #include "media/base/media.h"
 #include "net/base/net_errors.h"
@@ skipping 506 matching lines @@
 
 void RenderThreadImpl::SetResourceDispatcherDelegate(
     ResourceDispatcherDelegate* delegate) {
   resource_dispatcher()->set_delegate(delegate);
 }
 
 void RenderThreadImpl::WidgetHidden() {
   DCHECK(hidden_widget_count_ < widget_count_);
   hidden_widget_count_++;
 
+#if !defined(DISCARDABLE_MEMORY_SUPPORTED_NATIVELY)

[nduca, 2013/06/20 19:56:45]

i think we should always call the manager. there may be other systems that the
manager kicks.

+  RenderProcessVisibilityManager* manager =
+      RenderProcessVisibilityManager::GetInstance();
+  manager->WidgetVisibilityChanged(false);
+#endif
+
   if (!GetContentClient()->renderer()->RunIdleHandlerWhenWidgetsHidden()) {
     return;
   }
 
   if (widget_count_ && hidden_widget_count_ == widget_count_)
     ScheduleIdleHandler(kInitialIdleHandlerDelayMs);
 }
 
 void RenderThreadImpl::WidgetRestored() {
   DCHECK_GT(hidden_widget_count_, 0);
   hidden_widget_count_--;
+
+#if !defined(DISCARDABLE_MEMORY_SUPPORTED_NATIVELY)
+  RenderProcessVisibilityManager* manager =
+      RenderProcessVisibilityManager::GetInstance();
+  manager->WidgetVisibilityChanged(true);
+#endif
+
   if (!GetContentClient()->renderer()->RunIdleHandlerWhenWidgetsHidden()) {
     return;
   }
 
   ScheduleIdleHandler(kLongIdleHandlerDelayMs);
 }
 
 void RenderThreadImpl::EnsureWebKitInitialized() {
   if (webkit_platform_support_)
     return;
@@ skipping 611 matching lines @@
 
 void RenderThreadImpl::SetFlingCurveParameters(
     const std::vector<float>& new_touchpad,
     const std::vector<float>& new_touchscreen) {
   webkit_platform_support_->SetFlingCurveParameters(new_touchpad,
                                                     new_touchscreen);
 
 }
 
 }  // namespace content