Plugin Power Saver: Make PepperPluginInstanceThrottler interface public.

content/renderer/pepper/plugin_instance_throttler_impl.cc

Index: content/renderer/pepper/plugin_instance_throttler_impl.cc
diff --git a/content/renderer/pepper/pepper_plugin_instance_throttler.cc b/content/renderer/pepper/plugin_instance_throttler_impl.cc
similarity index 33%
rename from content/renderer/pepper/pepper_plugin_instance_throttler.cc
rename to content/renderer/pepper/plugin_instance_throttler_impl.cc
index 81382093e84ee05fd4966e6754e7617d2a5d1aa3..ea06846f786539c2979415a4d0873229e898008b 100644
--- a/content/renderer/pepper/pepper_plugin_instance_throttler.cc
+++ b/content/renderer/pepper/plugin_instance_throttler_impl.cc
@@ -2,12 +2,12 @@
 // 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_throttler.h"
+#include "content/renderer/pepper/plugin_instance_throttler_impl.h"
 
 #include "base/metrics/histogram.h"
-#include "base/metrics/sparse_histogram.h"
 #include "base/time/time.h"
 #include "content/public/common/content_constants.h"
+#include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_thread.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "ui/gfx/color_utils.h"
@@ -17,70 +17,13 @@ namespace content {
 
 namespace {
 
-static const int kInfiniteRatio = 99999;
-
-#define UMA_HISTOGRAM_ASPECT_RATIO(name, width, height) \
-  UMA_HISTOGRAM_SPARSE_SLOWLY(                          \
-      name, (height) ? ((width)*100) / (height) : kInfiniteRatio);
-
-// Histogram tracking prevalence of tiny Flash instances. Units in pixels.
-enum PluginFlashTinyContentSize {
-  TINY_CONTENT_SIZE_1_1 = 0,
-  TINY_CONTENT_SIZE_5_5 = 1,
-  TINY_CONTENT_SIZE_10_10 = 2,
-  TINY_CONTENT_SIZE_LARGE = 3,
-  TINY_CONTENT_SIZE_NUM_ITEMS
-};
-
-const char kFlashClickSizeAspectRatioHistogram[] =
-    "Plugin.Flash.ClickSize.AspectRatio";
-const char kFlashClickSizeHeightHistogram[] = "Plugin.Flash.ClickSize.Height";
-const char kFlashClickSizeWidthHistogram[] = "Plugin.Flash.ClickSize.Width";
-const char kFlashTinyContentSizeHistogram[] = "Plugin.Flash.TinyContentSize";
 const char kPowerSaverUnthrottleHistogram[] = "Plugin.PowerSaver.Unthrottle";
 
-// Record size metrics for all Flash instances.
-void RecordFlashSizeMetric(int width, int height) {
-  PluginFlashTinyContentSize size = TINY_CONTENT_SIZE_LARGE;
-
-  if (width <= 1 && height <= 1)
-    size = TINY_CONTENT_SIZE_1_1;
-  else if (width <= 5 && height <= 5)
-    size = TINY_CONTENT_SIZE_5_5;
-  else if (width <= 10 && height <= 10)
-    size = TINY_CONTENT_SIZE_10_10;
-
-  UMA_HISTOGRAM_ENUMERATION(kFlashTinyContentSizeHistogram, size,
-                            TINY_CONTENT_SIZE_NUM_ITEMS);
-}
-
 void RecordUnthrottleMethodMetric(
-    PepperPluginInstanceThrottler::PowerSaverUnthrottleMethod method) {
+    PluginInstanceThrottlerImpl::PowerSaverUnthrottleMethod method) {
   UMA_HISTOGRAM_ENUMERATION(
       kPowerSaverUnthrottleHistogram, method,
-      PepperPluginInstanceThrottler::UNTHROTTLE_METHOD_NUM_ITEMS);
-}
-
-// Records size metrics for Flash instances that are clicked.
-void RecordFlashClickSizeMetric(int width, int height) {
-  base::HistogramBase* width_histogram = base::LinearHistogram::FactoryGet(
-      kFlashClickSizeWidthHistogram,
-      0,    // minimum width
-      500,  // maximum width
-      100,  // number of buckets.
-      base::HistogramBase::kUmaTargetedHistogramFlag);
-  width_histogram->Add(width);
-
-  base::HistogramBase* height_histogram = base::LinearHistogram::FactoryGet(
-      kFlashClickSizeHeightHistogram,
-      0,    // minimum height
-      400,  // maximum height
-      100,  // number of buckets.
-      base::HistogramBase::kUmaTargetedHistogramFlag);
-  height_histogram->Add(height);
-
-  UMA_HISTOGRAM_ASPECT_RATIO(kFlashClickSizeAspectRatioHistogram, width,
-                             height);
+      PluginInstanceThrottler::UNTHROTTLE_METHOD_NUM_ITEMS);
 }
 
 // When we give up waiting for a suitable preview frame, and simply suspend
@@ -96,59 +39,61 @@ const int kMinimumConsecutiveInterestingFrames = 4;
 
 }  // namespace
 
-PepperPluginInstanceThrottler::PepperPluginInstanceThrottler(
+PluginInstanceThrottlerImpl::PluginInstanceThrottlerImpl(
     RenderFrame* frame,
-    const blink::WebRect& bounds,
-    bool is_flash_plugin,
     const GURL& plugin_url,
-    RenderFrame::PluginPowerSaverMode power_saver_mode,
-    const base::Closure& throttle_change_callback)
-    : bounds_(bounds),
-      throttle_change_callback_(throttle_change_callback),
-      is_flash_plugin_(is_flash_plugin),
-      needs_representative_keyframe_(false),
+    bool power_saver_enabled)
+    : state_(power_saver_enabled ? POWER_SAVER_ENABLED_AWAITING_KEYFRAME
+                                 : POWER_SAVER_DISABLED),
       consecutive_interesting_frames_(0),
-      has_been_clicked_(false),
-      power_saver_enabled_(false),
-      is_peripheral_content_(power_saver_mode !=
-                             RenderFrame::POWER_SAVER_MODE_ESSENTIAL),
-      plugin_throttled_(false),
       weak_factory_(this) {
-  if (is_flash_plugin_ && RenderThread::Get()) {
-    RenderThread::Get()->RecordAction(
-        base::UserMetricsAction("Flash.PluginInstanceCreated"));
-    RecordFlashSizeMetric(bounds.width, bounds.height);
-  }
-
-  power_saver_enabled_ =
-      is_flash_plugin_ &&
-      power_saver_mode == RenderFrame::POWER_SAVER_MODE_PERIPHERAL_THROTTLED;
-
-  GURL content_origin = plugin_url.GetOrigin();
-
   // To collect UMAs, register peripheral content even if power saver disabled.
   if (frame) {
     frame->RegisterPeripheralPlugin(
-        content_origin,
-        base::Bind(&PepperPluginInstanceThrottler::DisablePowerSaver,
+        plugin_url.GetOrigin(),
+        base::Bind(&PluginInstanceThrottlerImpl::MarkPluginEssential,
                    weak_factory_.GetWeakPtr(), UNTHROTTLE_METHOD_BY_WHITELIST));
   }
 
-  if (power_saver_enabled_) {
-    needs_representative_keyframe_ = true;
+  if (power_saver_enabled) {
     base::MessageLoop::current()->PostDelayedTask(
-        FROM_HERE,
-        base::Bind(&PepperPluginInstanceThrottler::SetPluginThrottled,
-                   weak_factory_.GetWeakPtr(), true /* throttled */),
+        FROM_HERE, base::Bind(&PluginInstanceThrottlerImpl::EngageThrottle,
+                              weak_factory_.GetWeakPtr()),
         base::TimeDelta::FromMilliseconds(kThrottleTimeout));
   }
 }
 
-PepperPluginInstanceThrottler::~PepperPluginInstanceThrottler() {
+PluginInstanceThrottlerImpl::~PluginInstanceThrottlerImpl() {
+}
+
+void PluginInstanceThrottlerImpl::AddObserver(Observer* observer) {
+  observer_list_.AddObserver(observer);
+}
+
+void PluginInstanceThrottlerImpl::RemoveObserver(Observer* observer) {
+  observer_list_.RemoveObserver(observer);
+}
+
+bool PluginInstanceThrottlerImpl::IsThrottled() const {
+  return state_ == POWER_SAVER_ENABLED_PLUGIN_THROTTLED;
+}
+
+void PluginInstanceThrottlerImpl::MarkPluginEssential(
+    PowerSaverUnthrottleMethod method) {
+  if (state_ == PLUGIN_INSTANCE_MARKED_ESSENTIAL)
+    return;
+
+  bool was_throttled = IsThrottled();
+  state_ = PLUGIN_INSTANCE_MARKED_ESSENTIAL;
+  RecordUnthrottleMethodMetric(method);
+
+  if (was_throttled)
+    FOR_EACH_OBSERVER(Observer, observer_list_, OnThrottleStateChange());
 }
 
-void PepperPluginInstanceThrottler::OnImageFlush(const SkBitmap* bitmap) {
-  if (!needs_representative_keyframe_ || !bitmap)
+void PluginInstanceThrottlerImpl::OnImageFlush(const SkBitmap* bitmap) {
+  DCHECK(needs_representative_keyframe());

[Lei Zhang, 2015/01/16 00:19:32]

Can this DCHECK fail? What if the MarkPluginEssential() happens before the
plugin flushes?

[tommycli, 2015/01/16 00:51:56]

It can't fail right now. The only caller is pepper_graphics_2d_host.cc and that
checks that needs_representative_keyframe() is true in its conditional.

+  if (!bitmap)
     return;
 
   double boring_score = color_utils::CalculateBoringScore(*bitmap);
@@ -158,10 +103,10 @@ void PepperPluginInstanceThrottler::OnImageFlush(const SkBitmap* bitmap) {
     consecutive_interesting_frames_ = 0;
 
   if (consecutive_interesting_frames_ >= kMinimumConsecutiveInterestingFrames)
-    SetPluginThrottled(true);
+    EngageThrottle();
 }
 
-bool PepperPluginInstanceThrottler::ConsumeInputEvent(
+bool PluginInstanceThrottlerImpl::ConsumeInputEvent(
     const blink::WebInputEvent& event) {
   // Always allow right-clicks through so users may verify it's a plug-in.
   // TODO(tommycli): We should instead show a custom context menu (probably
@@ -170,52 +115,23 @@ bool PepperPluginInstanceThrottler::ConsumeInputEvent(
   if (event.modifiers & blink::WebInputEvent::Modifiers::RightButtonDown)
     return false;
 
-  if (!has_been_clicked_ && is_flash_plugin_ &&
-      event.type == blink::WebInputEvent::MouseDown &&
+  if (state_ != PLUGIN_INSTANCE_MARKED_ESSENTIAL &&
+      event.type == blink::WebInputEvent::MouseUp &&
       (event.modifiers & blink::WebInputEvent::LeftButtonDown)) {
-    has_been_clicked_ = true;
-    RecordFlashClickSizeMetric(bounds_.width, bounds_.height);
-  }
-
-  if (is_peripheral_content_ && event.type == blink::WebInputEvent::MouseUp &&
-      (event.modifiers & blink::WebInputEvent::LeftButtonDown)) {
-    is_peripheral_content_ = false;
-    power_saver_enabled_ = false;
-    needs_representative_keyframe_ = false;
-
-    RecordUnthrottleMethodMetric(UNTHROTTLE_METHOD_BY_CLICK);
-
-    if (plugin_throttled_) {
-      SetPluginThrottled(false /* throttled */);
-      return true;
-    }
+    bool was_throttled = IsThrottled();
+    MarkPluginEssential(UNTHROTTLE_METHOD_BY_CLICK);
+    return was_throttled;
   }
 
-  return plugin_throttled_;
+  return IsThrottled();
 }
 
-void PepperPluginInstanceThrottler::DisablePowerSaver(
-    PowerSaverUnthrottleMethod method) {
-  if (!is_peripheral_content_)
+void PluginInstanceThrottlerImpl::EngageThrottle() {
+  if (state_ != POWER_SAVER_ENABLED_AWAITING_KEYFRAME)
     return;
 
-  is_peripheral_content_ = false;
-  power_saver_enabled_ = false;
-  SetPluginThrottled(false);
-
-  RecordUnthrottleMethodMetric(method);
-}
-
-void PepperPluginInstanceThrottler::SetPluginThrottled(bool throttled) {
-  // Do not throttle if we've already disabled power saver.
-  if (!power_saver_enabled_ && throttled)
-    return;
-
-  // Once we change the throttle state, we will never need the snapshot again.
-  needs_representative_keyframe_ = false;
-
-  plugin_throttled_ = throttled;
-  throttle_change_callback_.Run();
+  state_ = POWER_SAVER_ENABLED_PLUGIN_THROTTLED;
+  FOR_EACH_OBSERVER(Observer, observer_list_, OnThrottleStateChange());
 }
 
 }  // namespace content