Update a webview plugin's WebView's lifecycle immediately after resizing.

components/plugins/renderer/loadable_plugin_placeholder.cc

 // Copyright 2015 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 "components/plugins/renderer/loadable_plugin_placeholder.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/json/string_escape.h"
@@ skipping 17 matching lines @@
 #include "third_party/WebKit/public/web/WebView.h"
 #include "url/gurl.h"
 #include "url/origin.h"
 
 using base::UserMetricsAction;
 using content::PluginInstanceThrottler;
 using content::RenderThread;
 
 namespace plugins {
 
-// TODO(tommycli): After a size update, re-check the size after this delay, as
-// Blink can report incorrect sizes to plugins while the compositing state is
-// dirty. Chosen because it seems to work.
-const int kSizeChangeRecheckDelayMilliseconds = 100;

[chrishtr, 2016/03/04 05:22:09]

Strictly speaking, the change to this file has to be in the same CL as the other
one,
since it is not required to fix the referenced bug.

But timers like this are bad, especially since they introduce race conditions
that are very hard
to debug and reproduce.

-
 void LoadablePluginPlaceholder::BlockForPowerSaverPoster() {
   DCHECK(!is_blocked_for_power_saver_poster_);
   is_blocked_for_power_saver_poster_ = true;
 
   render_frame()->RegisterPeripheralPlugin(
       url::Origin(GURL(GetPluginParams().url)),
       base::Bind(&LoadablePluginPlaceholder::MarkPluginEssential,
                  weak_factory_.GetWeakPtr(),
                  PluginInstanceThrottler::UNTHROTTLE_METHOD_BY_WHITELIST));
 }
@@ skipping 140 matching lines @@
   if (!power_saver_enabled_ || !finished_loading_)
     return;
 
   // Only update the unobscured rect during the recheck phase. Also early exit
   // to prevent reentrancy issues.
   if (in_size_recheck_) {
     unobscured_rect_ = unobscured_rect;
     return;
   }
 
-  if (!size_update_timer_.IsRunning()) {
-    // TODO(tommycli): We have to post a delayed task to recheck the size, as
-    // Blink can report wrong sizes for partially obscured plugins while the
-    // compositing state is dirty. https://crbug.com/343769
-    size_update_timer_.Start(
-        FROM_HERE,
-        base::TimeDelta::FromMilliseconds(kSizeChangeRecheckDelayMilliseconds),
-        base::Bind(&LoadablePluginPlaceholder::RecheckSizeAndMaybeUnthrottle,
-                   weak_factory_.GetWeakPtr()));
-  }
+  RecheckSizeAndMaybeUnthrottle();
 }
 
 void LoadablePluginPlaceholder::WasShown() {
   if (is_blocked_for_background_tab_) {
     is_blocked_for_background_tab_ = false;
     if (!LoadingBlocked())
       LoadPlugin();
   }
 }
 
@@ skipping 153 matching lines @@
               content::RenderFrame::CONTENT_STATUS_ESSENTIAL_CROSS_ORIGIN_BIG) {
         render_frame()->WhitelistContentOrigin(content_origin);
       }
     }
 
     heuristic_run_before_ = true;
   }
 }
 
 }  // namespace plugins