Introduce WebInputMethodController to blink

components/test_runner/web_widget_test_client.cc

Index: components/test_runner/web_widget_test_client.cc
diff --git a/components/test_runner/web_widget_test_client.cc b/components/test_runner/web_widget_test_client.cc
index c38af4205d2721d2a65b6782e588728d8231df2a..582d9324a2488a96e5677edc57904037626e3b79 100644
--- a/components/test_runner/web_widget_test_client.cc
+++ b/components/test_runner/web_widget_test_client.cc
@@ -17,7 +17,11 @@
 #include "components/test_runner/web_view_test_proxy.h"
 #include "components/test_runner/web_widget_test_proxy.h"
 #include "third_party/WebKit/public/platform/WebScreenInfo.h"
+#include "third_party/WebKit/public/web/WebFrameWidget.h"
+#include "third_party/WebKit/public/web/WebInputMethodController.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "third_party/WebKit/public/web/WebPagePopup.h"
+#include "third_party/WebKit/public/web/WebView.h"
 #include "third_party/WebKit/public/web/WebWidget.h"
 
 namespace test_runner {
@@ -103,9 +107,22 @@ void WebWidgetTestClient::setToolTipText(const blink::WebString& text,
 void WebWidgetTestClient::resetInputMethod() {
   // If a composition text exists, then we need to let the browser process
   // to cancel the input method's ongoing composition session.
-  if (web_widget_test_proxy_base_)
-    web_widget_test_proxy_base_->web_widget()->finishComposingText(
+  blink::WebFrameWidget* frameWidget = nullptr;

[lfg, 2016/09/16 20:17:09]

frame_widget

[EhsanK, 2016/09/20 15:38:29]

Acknowledged.

+  if (web_widget_test_proxy_base_ &&
+      web_widget_test_proxy_base_->web_widget()->isWebFrameWidget()) {
+    frameWidget = static_cast<blink::WebFrameWidget*>(
+        web_widget_test_proxy_base_->web_widget());
+  } else if (web_view_test_proxy_base_) {
+    blink::WebLocalFrame* mainFrame =

[lfg, 2016/09/16 20:17:09]

main_frame

[EhsanK, 2016/09/20 15:38:29]

Acknowledged.

+        web_view_test_proxy_base_->web_view()->mainFrame()->toWebLocalFrame();
+    DCHECK(mainFrame);
+    frameWidget = mainFrame->frameWidget();
+  }
+
+  if (frameWidget && frameWidget->getActiveWebInputMethodController()) {
+    frameWidget->getActiveWebInputMethodController()->finishComposingText(
         blink::WebWidget::KeepSelection);

[lfg, 2016/09/16 20:17:09]

Why this method is implemented using KeepSelection, but the implementation in
RenderWidget uses DoNotKeepSelection?

[EhsanK, 2016/09/20 15:38:29]

The one with DoNotKeepSelection sounds more correct to me (for RenderWidget).
But I am not sure why it is KeepSelection here. Adding aelias@ as a reviewer
since he made this change.

[aelias_OOO_until_Jul13, 2016/09/21 08:28:02]

This was a mistake, you can change it to DoNotKeepSelectiom.  KeepSelection is
just for use by Android and Android-related tests.

[lfg, 2016/09/21 16:56:14]

I think we should be able to just remove this override, and remove the overrides
in WebWidgetTestProxy and WebViewTestProxy, which should make the RenderWidget
handle the calls.

[EhsanK, 2016/09/26 20:54:29]

The difference would be that here we do not send an IPC back to the browser. In
RenderWidget we do. Removing these methods also causes the following test to
fail all the time:
fast/events/composition-event-source-device-event-sender.html
I ran the test locally on Linux. I think it might need more work.

[lfg, 2016/09/29 14:16:41]

I think its worth investigating these failures and understanding them. All other
IPC methods go through RenderWidget and send IPCs to the browser process, I
don't see why this should be different.

[EhsanK, 2016/11/01 15:46:04]

I dug deeper and here is what I found:
In the test mentioned, we focus an <input> and setMarkText using
TextInputController API in components/test_runner/ and then blur the input. When
blurring, specifically, we resetInputMethod which will cause some events firing
for composition.

The problem was, javascript generated input.focus() is not user gesture so it
the Element::focus() path will not call IME methods to set text input state.

The solution was to either, manually call ResetInputMethod through JS binding,
or, mark the next event as gesture event. I did the latter but the former is
also possible. I though this way at least we are describing a valid scenario
which would work on Chrome. By forcefully calling a reset method we might be
mocking too much.

Adding lanwei@ for her opinion on the test changes.

+  }
 }
 
 }  // namespace test_runner