Plugin Power Saver: Add some UMAs to test plugins in wild.

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 "base/callback.h"
+#include "base/metrics/histogram.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 {
 
+// Initial decision of the peripheral content decision.
+// These numeric values are used in UMA logs; do not change them.
+enum PeripheralHeuristicDecision {
+  HEURISTIC_DECISION_PERIPHERAL = 0,
+  HEURISTIC_DECISION_ESSENTIAL_SAME_ORIGIN = 1,
+  HEURISTIC_DECISION_ESSENTIAL_CROSS_ORIGIN_BIG = 2,
+  HEURISTIC_DECISION_ESSENTIAL_CROSS_ORIGIN_WHITELISTED = 3,
+  HEURISTIC_DECISION_NUM_ITEMS
+};
+
+const char kPeripheralHeuristicHistogram[] =
+    "Plugin.PowerSaverPeripheralHeuristic";
+
 // 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;
 
+void RecordDecisionMetric(PeripheralHeuristicDecision decision) {
+  UMA_HISTOGRAM_ENUMERATION(kPeripheralHeuristicHistogram, decision,
+                            HEURISTIC_DECISION_NUM_ITEMS);
+}
+
 }  // namespace
 
 PluginPowerSaverHelper::PeripheralPlugin::PeripheralPlugin(
     const GURL& content_origin,
     const base::Closure& unthrottle_callback)
     : content_origin(content_origin), unthrottle_callback(unthrottle_callback) {
 }
 
 PluginPowerSaverHelper::PeripheralPlugin::~PeripheralPlugin() {
 }
@@ skipping 48 matching lines @@
                                                    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())
+  if (main_frame->isWebRemoteFrame()) {
+    RecordDecisionMetric(HEURISTIC_DECISION_PERIPHERAL);
     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) {
+    RecordDecisionMetric(HEURISTIC_DECISION_ESSENTIAL_SAME_ORIGIN);
     *cross_origin = false;
     return false;
   }
 
   // Whitelisted plugin origins are also essential.
-  if (origin_whitelist_.count(content_origin))
+  if (origin_whitelist_.count(content_origin)) {
+    RecordDecisionMetric(HEURISTIC_DECISION_ESSENTIAL_CROSS_ORIGIN_WHITELISTED);
     return false;
+  }
 
   // Cross-origin plugin content is peripheral if smaller than a maximum size.
   bool content_is_small = width < kPeripheralContentMaxWidth ||
                           height < kPeripheralContentMaxHeight;
 
+  if (content_is_small)
+    RecordDecisionMetric(HEURISTIC_DECISION_PERIPHERAL);
+  else
+    RecordDecisionMetric(HEURISTIC_DECISION_ESSENTIAL_CROSS_ORIGIN_BIG);
+
   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