Fix synchronization in SitePerProcessTextInputManagerTest.SubframeKeyboardEditCommands.

chrome/browser/renderer_host/site_per_process_text_input_browsertest.cc

Index: chrome/browser/renderer_host/site_per_process_text_input_browsertest.cc
diff --git a/chrome/browser/renderer_host/site_per_process_text_input_browsertest.cc b/chrome/browser/renderer_host/site_per_process_text_input_browsertest.cc
index bf14dac20475f4f7df68553de9e5cce34ea7091f..d666f55523490c149a0491eebb8b0fc2475f2c3f 100644
--- a/chrome/browser/renderer_host/site_per_process_text_input_browsertest.cc
+++ b/chrome/browser/renderer_host/site_per_process_text_input_browsertest.cc
@@ -1115,16 +1115,28 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessTextInputManagerTest,
   content::RenderFrameHost* child =
       ChildFrameAt(web_contents->GetMainFrame(), 0);
   std::string result;
+  std::string script =
+      "function onInput(e) {"
+      "  domAutomationController.setAutomationId(0);"
+      "  domAutomationController.send(getInputFieldText());"
+      "}"
+      "inputField = document.getElementById('text-field');"
+      "inputField.addEventListener('input', onInput, false);";
+  EXPECT_TRUE(ExecuteScript(child, script));
   EXPECT_TRUE(ExecuteScriptAndExtractString(
       child, "window.focus(); focusInputField();", &result));
   EXPECT_EQ("input-focus", result);
   EXPECT_EQ(child, web_contents->GetFocusedFrame());
 
   // Generate a couple of keystrokes, which will be routed to the subframe.
+  content::DOMMessageQueue msg_queue;
+  std::string reply;
   SimulateKeyPress(web_contents, ui::DomKey::FromCharacter('1'),
                    ui::DomCode::DIGIT1, ui::VKEY_1, false, false, false, false);
+  EXPECT_TRUE(msg_queue.WaitForMessage(&reply));
   SimulateKeyPress(web_contents, ui::DomKey::FromCharacter('2'),
                    ui::DomCode::DIGIT2, ui::VKEY_2, false, false, false, false);
+  EXPECT_TRUE(msg_queue.WaitForMessage(&reply));
 
   // Verify that the input field in the subframe received the keystrokes.
   EXPECT_TRUE(ExecuteScriptAndExtractString(