Plugin Power Saver: Implement size-based heuristic for peripheral content.

content/renderer/pepper/plugin_power_saver_helper.cc

Index: content/renderer/pepper/plugin_power_saver_helper.cc
diff --git a/content/renderer/pepper/plugin_power_saver_helper.cc b/content/renderer/pepper/plugin_power_saver_helper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..13c079ee1c876503c7f49eeb5416aaa4958b3265
--- /dev/null
+++ b/content/renderer/pepper/plugin_power_saver_helper.cc
@@ -0,0 +1,128 @@
+// Copyright 2014 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 "base/callback.h"
+#include "content/common/frame_messages.h"
+#include "content/public/renderer/document_state.h"
+#include "content/public/renderer/navigation_state.h"
+#include "content/public/renderer/render_frame.h"
+#include "content/renderer/pepper/plugin_power_saver_helper.h"
+#include "third_party/WebKit/public/web/WebDocument.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
+#include "third_party/WebKit/public/web/WebView.h"
+
+namespace content {
+
+namespace {
+
+// Maximum dimensions plug-in content may have while still being considered
+// peripheral content. These match the sizes used by Safari.
+const int kPeripheralContentMaxWidth = 400;
+const int kPeripheralContentMaxHeight = 300;
+
+}  // namespace
+
+PluginPowerSaverHelper::PeripheralPlugin::PeripheralPlugin(
+    const GURL& content_origin,
+    const base::Closure& unthrottle_callback)
+    : content_origin(content_origin), unthrottle_callback(unthrottle_callback) {
+}
+
+PluginPowerSaverHelper::PeripheralPlugin::~PeripheralPlugin() {
+}
+
+PluginPowerSaverHelper::PluginPowerSaverHelper(RenderFrame* render_frame)
+    : RenderFrameObserver(render_frame) {
+}
+
+PluginPowerSaverHelper::~PluginPowerSaverHelper() {
+}
+
+void PluginPowerSaverHelper::DidCommitProvisionalLoad(bool is_new_navigation) {
+  blink::WebFrame* frame = render_frame()->GetWebFrame();
+  if (frame->parent())
+    return;  // Not a top-level navigation.
+
+  DocumentState* document_state =
+      DocumentState::FromDataSource(frame->dataSource());
+  NavigationState* navigation_state = document_state->navigation_state();
+  if (!navigation_state->was_within_same_page())
+    origin_whitelist_.clear();
+}
+
+bool PluginPowerSaverHelper::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(PluginPowerSaverHelper, message)
+    IPC_MESSAGE_HANDLER(FrameMsg_UpdatePluginContentOriginWhitelist,
+                        OnUpdatePluginContentOriginWhitelist)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void PluginPowerSaverHelper::OnUpdatePluginContentOriginWhitelist(
+    const std::set<GURL>& origin_whitelist) {
+  origin_whitelist_ = origin_whitelist;
+
+  // Check throttled plugin instances to see if any can be unthrottled.
+  auto it = peripheral_plugins_.begin();
+  while (it != peripheral_plugins_.end()) {
+    if (origin_whitelist.count(it->content_origin)) {
+      it->unthrottle_callback.Run();
+      it = peripheral_plugins_.erase(it);
+    } else {
+      ++it;
+    }
+  }
+}
+
+bool PluginPowerSaverHelper::ShouldThrottleContent(const GURL& content_origin,
+                                                   int width,
+                                                   int height,
+                                                   bool* cross_origin) const {
+  DCHECK(cross_origin);
+  *cross_origin = true;
+
+  // TODO(alexmos): Update this to use the origin of the RemoteFrame when 426512
+  // is fixed. For now, case 3 in the class level comment doesn't work in
+  // --site-per-process mode.
+  blink::WebFrame* main_frame =
+      render_frame()->GetWebFrame()->view()->mainFrame();
+  if (main_frame->isWebRemoteFrame())
+    return true;
+
+  // All same-origin plugin content is essential.
+  GURL main_frame_origin = GURL(main_frame->document().url()).GetOrigin();
+  if (content_origin == main_frame_origin) {
+    *cross_origin = false;
+    return false;
+  }
+
+  // Whitelisted plugin origins are also essential.
+  if (origin_whitelist_.count(content_origin))
+    return false;
+
+  // Cross-origin plugin content is peripheral if smaller than a maximum size.
+  bool content_is_small = width < kPeripheralContentMaxWidth ||
+                          height < kPeripheralContentMaxHeight;
+
+  return content_is_small;
+}
+
+void PluginPowerSaverHelper::RegisterPeripheralPlugin(
+    const GURL& content_origin,
+    const base::Closure& unthrottle_callback) {
+  peripheral_plugins_.push_back(
+      PeripheralPlugin(content_origin, unthrottle_callback));
+}
+
+void PluginPowerSaverHelper::WhitelistContentOrigin(
+    const GURL& content_origin) {
+  if (origin_whitelist_.insert(content_origin).second) {
+    Send(new FrameHostMsg_PluginContentOriginAllowed(
+        render_frame()->GetRoutingID(), content_origin));
+  }
+}
+
+}  // namespace content