Don't defer quitting in ExecuteScript and other helpers that use DOMMessageQueue.

chrome/browser/plugins/flash_permission_browsertest.cc

Index: chrome/browser/plugins/flash_permission_browsertest.cc
diff --git a/chrome/browser/plugins/flash_permission_browsertest.cc b/chrome/browser/plugins/flash_permission_browsertest.cc
index 5a934dd64c6ab4a3f07d9e6365ab9f3f4a3c1ec0..c1db46dd3fb8ae8cbf9d1f755597e931bf16e81f 100644
--- a/chrome/browser/plugins/flash_permission_browsertest.cc
+++ b/chrome/browser/plugins/flash_permission_browsertest.cc
@@ -17,6 +17,27 @@
 #include "third_party/WebKit/public/platform/WebInputEvent.h"
 #include "url/gurl.h"
 
+namespace {
+
+class PageReloadWaiter {
+ public:
+  explicit PageReloadWaiter(content::WebContents* web_contents)
+      : web_contents_(web_contents),
+        navigation_observer_(web_contents,
+                             web_contents->GetLastCommittedURL()) {}
+
+  bool Wait() {
+    navigation_observer_.WaitForNavigationFinished();
+    return content::WaitForLoadStop(web_contents_);
+  }
+
+ private:
+  content::WebContents* web_contents_;
+  content::TestNavigationManager navigation_observer_;
+};
+
+}  // namespace
+
 class FlashPermissionBrowserTest : public PermissionsBrowserTest {
  public:
   FlashPermissionBrowserTest()
@@ -44,18 +65,21 @@ class FlashPermissionBrowserTest : public PermissionsBrowserTest {
     if (prompt_factory()->response_type() ==
         PermissionRequestManager::ACCEPT_ALL) {
       // If the prompt will be allowed, we need to wait for the page to refresh.
-      content::TestNavigationManager observer(
-          GetWebContents(), GetWebContents()->GetLastCommittedURL());
+      PageReloadWaiter reload_waiter(GetWebContents());
       EXPECT_TRUE(RunScriptReturnBool("triggerPrompt();"));
-      observer.WaitForNavigationFinished();
+      EXPECT_TRUE(reload_waiter.Wait());
     } else {
       EXPECT_TRUE(RunScriptReturnBool("triggerPrompt();"));
     }
   }
 
   bool FeatureUsageSucceeds() override {
-    // Wait until the page is refreshed before testing whether flash is enabled
-    // or disabled.
+    // If flash should have been blocked, reload the page to be sure that it is
+    // blocked.
+    //
+    // NB: In cases where flash is allowed the page reloads automatically,
+    // and tests should always wait for that reload to finish before calling
+    // this method.
     ui_test_utils::NavigateToURL(browser(),
                                  GetWebContents()->GetLastCommittedURL());
     // If either flash with or without fallback content runs successfully it
@@ -86,7 +110,11 @@ IN_PROC_BROWSER_TEST_F(FlashPermissionBrowserTest, CommonSucceedsIfAllowed) {
 IN_PROC_BROWSER_TEST_F(FlashPermissionBrowserTest, TriggerPromptViaNewWindow) {
   EXPECT_EQ(0, prompt_factory()->total_request_count());
   prompt_factory()->set_response_type(PermissionRequestManager::ACCEPT_ALL);
+  // FlashPermissionContext::UpdateTabContext will reload the page, we'll have
+  // to wait until it is ready.
+  PageReloadWaiter reload_waiter(GetWebContents());
   EXPECT_TRUE(RunScriptReturnBool("triggerPromptViaNewWindow();"));
+  EXPECT_TRUE(reload_waiter.Wait());
 
   EXPECT_TRUE(FeatureUsageSucceeds());
   EXPECT_EQ(1, prompt_factory()->total_request_count());
@@ -98,12 +126,12 @@ IN_PROC_BROWSER_TEST_F(FlashPermissionBrowserTest,
   EXPECT_FALSE(FeatureUsageSucceeds());
   prompt_factory()->set_response_type(PermissionRequestManager::ACCEPT_ALL);
   // We need to simulate a mouse click to trigger the placeholder to prompt.
-  content::TestNavigationManager observer(
-      GetWebContents(), GetWebContents()->GetLastCommittedURL());
+  // When the prompt is auto-accepted, the page will be reloaded.
+  PageReloadWaiter reload_waiter(GetWebContents());
   content::SimulateMouseClickAt(GetWebContents(), 0 /* modifiers */,
                                 blink::WebMouseEvent::Button::Left,
                                 gfx::Point(50, 50));
-  observer.WaitForNavigationFinished();
+  EXPECT_TRUE(reload_waiter.Wait());
 
   EXPECT_TRUE(FeatureUsageSucceeds());
   EXPECT_EQ(1, prompt_factory()->total_request_count());