Plugin Power Saver: Enable JS access to throttled plugins.

chrome/browser/plugins/plugin_power_saver_browsertest.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 "base/command_line.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/chrome_switches.h"
@@ skipping 19 matching lines @@
       "} else {"
       "  %s"
       "}",
       element_id.c_str(), test_script.data());
   std::string result;
   EXPECT_TRUE(
       content::ExecuteScriptAndExtractString(contents, script, &result));
   return result;
 }
 
-void VerifyPluginIsPlaceholderOnly(content::WebContents* contents,
-                                   const char* element_id) {
+// This also tests that we have JavaScript access to the underlying plugin.
+bool PluginLoaded(content::WebContents* contents, const char* element_id) {
   std::string result = RunTestScript(
       "if (plugin.postMessage === undefined) {"
-      "  window.domAutomationController.send('placeholder');"
+      "  window.domAutomationController.send('poster_only');"
       "} else {"
       "  window.domAutomationController.send('plugin_loaded');"
       "}",
       contents, element_id);
-  EXPECT_EQ("placeholder", result);
+  EXPECT_NE("error", result);
+  return result == "plugin_loaded";
 }
 
-void VerifyPluginIsPeripheral(content::WebContents* contents,
-                              const char* element_id) {
+void VerifyPluginIsThrottled(content::WebContents* contents,
+                             const char* element_id) {
   std::string result = RunTestScript(
       "function handleEvent(event) {"
-      "  if (event.data.isPeripheral !== undefined && "
-      "      event.data.source === 'getPowerSaverStatusResponse') {"

[Lei Zhang, 2015/05/07 23:15:59]

Do you still care about the event's data source?

[tommycli, 2015/05/08 00:49:00]

We don't care about the source anymore. We just care that all the three
conditions are fulfilled.

-      "    window.domAutomationController.send("
-      "        event.data.isPeripheral ? 'peripheral' : 'essential');"
+      "  if (event.data.isPeripheral && event.data.isThrottled && "
+      "      event.data.isHiddenForPlaceholder) {"
+      "    window.domAutomationController.send('throttled');"
       "    plugin.removeEventListener('message', handleEvent);"
       "  }"
       "}"
-      "if (plugin.postMessage === undefined) {"
-      "  window.domAutomationController.send('peripheral');"
-      "} else {"
-      "  plugin.addEventListener('message', handleEvent);"
+      "plugin.addEventListener('message', handleEvent);"
+      "if (plugin.postMessage !== undefined) {"

[Lei Zhang, 2015/05/07 23:15:59]

So previously, if plugin.postMessage is undefined, it would send() and
RunTestScript() would return. Now, the code does nothing. Is it relying on
handleEvent() to eventually call send(), or will this end up hanging and timing
out?

[tommycli, 2015/05/08 00:49:00]

Exactly. Now it expects that if there is no postMessage yet, the plugin will
send the "initial" status messages and we will catch those.

       "  plugin.postMessage('getPowerSaverStatus');"
       "}",
       contents, element_id);
-  EXPECT_EQ("peripheral", result);
+  EXPECT_EQ("throttled", result);
+
+  // Page should continue to have JavaScript access to all throttled plugins.
+  EXPECT_TRUE(PluginLoaded(contents, element_id));
 }
 
 void VerifyPluginMarkedEssential(content::WebContents* contents,
                                  const char* element_id) {
   std::string result = RunTestScript(
       "function handleEvent(event) {"
       "  if (event.data.isPeripheral === false) {"
       "    window.domAutomationController.send('essential');"
       "    plugin.removeEventListener('message', handleEvent);"
       "  }"
       "}"
       "plugin.addEventListener('message', handleEvent);"
       "if (plugin.postMessage !== undefined) {"
       "  plugin.postMessage('getPowerSaverStatus');"
       "}",
       contents, element_id);
   EXPECT_EQ("essential", result);
+  EXPECT_TRUE(PluginLoaded(contents, element_id));
 }
 
 }  // namespace
 
 class PluginPowerSaverBrowserTest : virtual public InProcessBrowserTest {
  public:
   void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitch(switches::kEnablePluginPowerSaver);
     command_line->AppendSwitch(switches::kEnablePepperTesting);
 
@@ skipping 30 matching lines @@
 };
 
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, SmallSameOrigin) {
   LoadHTML(
       "<object id='plugin' data='fake.swf' "
       "    type='application/x-ppapi-tests' width='400' height='100'>"
       "</object>");
   VerifyPluginMarkedEssential(GetActiveWebContents(), "plugin");
 }
 
-// Flaky: https://crbug.com/485160
-IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, DISABLED_SmallCrossOrigin) {
+IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, SmallCrossOrigin) {

[tommycli, 2015/05/07 17:23:00]

I believe this patch incidentally fixes this flaky test (but I am not sure).

[Bernhard Bauer, 2015/05/07 17:46:28]

Does it? I thought there was the race condition where we dispatch the click
before the inner HTML has loaded?

[tommycli, 2015/05/07 17:55:31]

Since we changed it to VerifyPluginIsThrottled, it should wait until
event.data.isHiddenForPlaceholder is true also. (See line 58)

Since throttler->SetHiddenForPlaceholder is only called in
DidFinishLoadingCallback, my theory is that in this particular case, the race
condition is resolved.

The remaining issue is for when there is no throttled plugin and we have a
poster image only. Then we have no notification for DidFinishLoadingCallback.

[Bernhard Bauer, 2015/05/07 18:23:26]

Acknowledged.

[Lei Zhang, 2015/05/07 23:15:59]

Can you add a comment to the top of VerifyPluginIsThrottled() to mention it
waits for the plugin to finish loading?

[tommycli, 2015/05/08 00:49:00]

Done.

   LoadHTML(
       "<object id='plugin' data='http://otherorigin.com/fake.swf' "
       "    type='application/x-ppapi-tests' width='400' height='100'>"
       "</object>");
-  VerifyPluginIsPeripheral(GetActiveWebContents(), "plugin");
+  VerifyPluginIsThrottled(GetActiveWebContents(), "plugin");
 
   SimulateClickAndAwaitMarkedEssential("plugin", gfx::Point(50, 50));
 }
 
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, LargeCrossOrigin) {
   LoadHTML(
       "<object id='plugin' data='http://otherorigin.com/fake.swf' "
       "    type='application/x-ppapi-tests' width='400' height='500'>"
       "</object>");
   VerifyPluginMarkedEssential(GetActiveWebContents(), "plugin");
@@ skipping 10 matching lines @@
       "<object id='plugin_legacy_syntax' type='application/x-ppapi-tests' "
       "    width='400' height='500'>"
       "  <param name='poster' value='snapshot1x.png 1x, snapshot2x.png 2x'>"
       "</object>"
       "<embed id='plugin_embed_src' type='application/x-ppapi-tests' "
       "    width='400' height='500' poster='snapshot1x.png'></embed>"
       "<embed id='plugin_embed_srcset' type='application/x-ppapi-tests' "
       "    width='400' height='500'"
       "    poster='snapshot1x.png 1x, snapshot2x.png 2x'></embed>");
 
-  VerifyPluginIsPlaceholderOnly(GetActiveWebContents(), "plugin_src");
-  VerifyPluginIsPlaceholderOnly(GetActiveWebContents(), "plugin_srcset");
-  VerifyPluginIsPlaceholderOnly(GetActiveWebContents(), "plugin_legacy_syntax");
-  VerifyPluginIsPlaceholderOnly(GetActiveWebContents(), "plugin_embed_src");
-  VerifyPluginIsPlaceholderOnly(GetActiveWebContents(), "plugin_embed_srcset");
+  EXPECT_FALSE(PluginLoaded(GetActiveWebContents(), "plugin_src"));
+  EXPECT_FALSE(PluginLoaded(GetActiveWebContents(), "plugin_srcset"));
+  EXPECT_FALSE(PluginLoaded(GetActiveWebContents(), "plugin_legacy_syntax"));
+  EXPECT_FALSE(PluginLoaded(GetActiveWebContents(), "plugin_embed_src"));
+  EXPECT_FALSE(PluginLoaded(GetActiveWebContents(), "plugin_embed_srcset"));
 }
 
 // flaky: crbug.com/481687
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest,
                        DISABLED_PluginMarkedEssentialAfterPosterClicked) {
   LoadHTML(
       "<object id='plugin' type='application/x-ppapi-tests' "
       "    width='400' height='100' poster='snapshot1x.png'></object>");
-  VerifyPluginIsPlaceholderOnly(GetActiveWebContents(), "plugin");
+  EXPECT_FALSE(PluginLoaded(GetActiveWebContents(), "plugin"));
 
   SimulateClickAndAwaitMarkedEssential("plugin", gfx::Point(50, 50));
 }
 
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, OriginWhitelisting) {
   LoadHTML(
       "<object id='plugin1' data='http://otherorigin.com/fake1.swf' "
       "    type='application/x-ppapi-tests' width='400' height='100'></object>"
       "<object id='plugin2' data='http://otherorigin.com/fake2.swf' "
       "    type='application/x-ppapi-tests' width='400' height='500'>"
       "</object>");
   VerifyPluginMarkedEssential(GetActiveWebContents(), "plugin1");
   VerifyPluginMarkedEssential(GetActiveWebContents(), "plugin2");
 }
 
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, LargeCrossOriginObscured) {
   LoadHTML(
       "<div style='width: 100px; height: 100px; overflow: hidden;'>"
       "  <object id='plugin' data='http://otherorigin.com/fake.swf' "
       "      type='application/x-ppapi-tests' width='400' height='500'>"
       "  </object>"
       "</div>");
-  VerifyPluginIsPeripheral(GetActiveWebContents(), "plugin");
+  VerifyPluginIsThrottled(GetActiveWebContents(), "plugin");
 }
 
 IN_PROC_BROWSER_TEST_F(PluginPowerSaverBrowserTest, BackgroundTabPlugins) {
   std::string url_str =
       "data:text/html;charset=utf-8,"
       "<object id='same_origin' type='application/x-ppapi-tests'></object>"
       "<object id='small_cross_origin' data='http://otherorigin.com/fake1.swf' "
       "   type='application/x-ppapi-tests' width='400' height='100'></object>";
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), GURL(url_str), NEW_BACKGROUND_TAB,
       ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
 
   ASSERT_EQ(2, browser()->tab_strip_model()->count());
   content::WebContents* background_contents =
       browser()->tab_strip_model()->GetWebContentsAt(1);
   EXPECT_TRUE(
       content::WaitForRenderFrameReady(background_contents->GetMainFrame()));
 
-  VerifyPluginIsPlaceholderOnly(background_contents, "same_origin");
-  VerifyPluginIsPlaceholderOnly(background_contents, "small_cross_origin");
+  EXPECT_FALSE(PluginLoaded(background_contents, "same_origin"));
+  EXPECT_FALSE(PluginLoaded(background_contents, "small_cross_origin"));
 
   browser()->tab_strip_model()->SelectNextTab();
   EXPECT_EQ(background_contents, GetActiveWebContents());
 
   VerifyPluginMarkedEssential(background_contents, "same_origin");
-  VerifyPluginIsPeripheral(background_contents, "small_cross_origin");
+  VerifyPluginIsThrottled(background_contents, "small_cross_origin");
 }