Plugin Power Saver: Improve Poster behavior for essential plugins.

content/renderer/pepper/plugin_power_saver_helper.cc

 // 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 "content/renderer/pepper/plugin_power_saver_helper.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
@@ skipping 83 matching lines @@
     *cross_origin_main_content = false;
 
   if (base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
           switches::kOverridePluginPowerSaverForTesting) == "always") {
     return true;
   }
 
   auto decision = PeripheralContentHeuristic::GetPeripheralStatus(
       origin_whitelist_, main_frame_origin, content_origin, width, height);
 
+  bool plugin_size_unknown = width < 0 || height < 0;
+  if (plugin_size_unknown) {

[groby-ooo-7-16, 2015/12/04 22:06:56]

Can you leave a comment why we record these here?

[tommycli, 2015/12/07 22:06:18]

Done. It's very non-obvious.

+    if (decision == PeripheralContentHeuristic::
+                        HEURISTIC_DECISION_ESSENTIAL_SAME_ORIGIN ||
+        decision == PeripheralContentHeuristic::
+                        HEURISTIC_DECISION_ESSENTIAL_CROSS_ORIGIN_WHITELISTED) {
+      UMA_HISTOGRAM_ENUMERATION(
+          kPeripheralHeuristicHistogram, decision,
+          PeripheralContentHeuristic::HEURISTIC_DECISION_NUM_ITEMS);
+      return false;
+    }
+
+    return true;
+  }
+
   UMA_HISTOGRAM_ENUMERATION(
       kPeripheralHeuristicHistogram, decision,
       PeripheralContentHeuristic::HEURISTIC_DECISION_NUM_ITEMS);
 
   if (decision == PeripheralContentHeuristic::
                       HEURISTIC_DECISION_ESSENTIAL_CROSS_ORIGIN_BIG &&
       cross_origin_main_content)
     *cross_origin_main_content = true;
 
   return decision == PeripheralContentHeuristic::HEURISTIC_DECISION_PERIPHERAL;
 }
 
 void PluginPowerSaverHelper::WhitelistContentOrigin(
     const url::Origin& content_origin) {
   if (origin_whitelist_.insert(content_origin).second) {
     Send(new FrameHostMsg_PluginContentOriginAllowed(
         render_frame()->GetRoutingID(), content_origin));
   }
 }
 
 }  // namespace content