Introduce WebInputMethodController to blink

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 57bb2085f61e3f419307f96fb827956bc7ba7206..d5bc6ce03fe5e2b3607966d3c19860952540babf 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -64,6 +64,7 @@
 #include "third_party/WebKit/public/platform/scheduler/renderer/renderer_scheduler.h"
 #include "third_party/WebKit/public/web/WebDeviceEmulationParams.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/WebNode.h"
 #include "third_party/WebKit/public/web/WebPagePopup.h"
@@ -106,6 +107,7 @@ using blink::WebDeviceEmulationParams;
 using blink::WebGestureEvent;
 using blink::WebInputEvent;
 using blink::WebInputEventResult;
+using blink::WebInputMethodController;
 using blink::WebKeyboardEvent;
 using blink::WebMouseEvent;
 using blink::WebMouseWheelEvent;
@@ -1396,7 +1398,10 @@ void RenderWidget::OnImeSetComposition(
   if (!ShouldHandleImeEvent())
     return;
   ImeEventGuard guard(this);
-  if (!GetWebWidget()->setComposition(
+  auto* controller = GetInputMethodController();

[Charlie Reis, 2016/11/02 20:57:38]

nit: Let's avoid auto here.  It's helpful to know what type this below, and
isn't saving much.  (I guess I'm ok with it in the cases below, where the
declaration is within a conditional.)

[EhsanK, 2016/11/02 22:16:34]

Acknowledged.

+  DCHECK(controller);
+  if (!controller ||
+      !controller->setComposition(
           text, WebVector<WebCompositionUnderline>(underlines), selection_start,
           selection_end)) {
     // If we failed to set the composition text, then we need to let the browser
@@ -1426,7 +1431,8 @@ void RenderWidget::OnImeCommitText(const base::string16& text,
     return;
   ImeEventGuard guard(this);
   input_handler_->set_handling_input_event(true);
-  GetWebWidget()->commitText(text, relative_cursor_pos);
+  if (auto* controller = GetInputMethodController())
+    controller->commitText(text, relative_cursor_pos);
   input_handler_->set_handling_input_event(false);
   UpdateCompositionInfo(false /* not an immediate request */);
 }
@@ -1444,9 +1450,11 @@ void RenderWidget::OnImeFinishComposingText(bool keep_selection) {
     return;
   ImeEventGuard guard(this);
   input_handler_->set_handling_input_event(true);
-  GetWebWidget()->finishComposingText(keep_selection
-                                      ? WebWidget::KeepSelection
-                                      : WebWidget::DoNotKeepSelection);
+  if (auto* controller = GetInputMethodController()) {
+    controller->finishComposingText(
+        keep_selection ? WebInputMethodController::KeepSelection
+                       : WebInputMethodController::DoNotKeepSelection);
+  }
   input_handler_->set_handling_input_event(false);
   UpdateCompositionInfo(false /* not an immediate request */);
 }
@@ -1953,7 +1961,10 @@ void RenderWidget::resetInputMethod() {
   if (text_input_type_ != ui::TEXT_INPUT_TYPE_NONE) {
     // If a composition text exists, then we need to let the browser process
     // to cancel the input method's ongoing composition session.
-    if (GetWebWidget()->finishComposingText(WebWidget::DoNotKeepSelection))
+    auto* controller = GetInputMethodController();
+    if (controller &&
+        controller->finishComposingText(
+            WebInputMethodController::DoNotKeepSelection))
       Send(new InputHostMsg_ImeCancelComposition(routing_id()));
   }
 
@@ -2094,4 +2105,13 @@ blink::WebWidget* RenderWidget::GetWebWidget() const {
   return webwidget_internal_;
 }
 
+blink::WebInputMethodController* RenderWidget::GetInputMethodController()
+    const {
+  // TODO(ekaramad): Will this DCHECK ever fire? Remove when GetWebWidget() is
+  // always a WebFrameWidget.
+  DCHECK(GetWebWidget()->isWebFrameWidget());

[Charlie Reis, 2016/11/02 20:57:38]

This can't be a DCHECK, since we'll get a potentially exploitable bad cast in
release builds if it's wrong.  Make it a CHECK (preferable if we don't think it
can fail) or return early if it fails.

[EhsanK, 2016/11/02 22:16:34]

I see. Thanks! I don't think we can have a WebWidget which is WebFrameWidget.
But I think lfg@ was mentioning a case this could have happened?

For now I made it a CHECK. lfg@ WDYT?

+  return static_cast<blink::WebFrameWidget*>(GetWebWidget())
+      ->getActiveWebInputMethodController();
+}
+
 }  // namespace content