IME events were not dispatched properly to Pepper.

A stub implementation for ShouldDispatchImeEventsToPepper was placed
on FrameWidget but was never implemented anywhere. Some methods called
the proper Client()->ShouldDispatchImeEventsToPepper code path, but
others ended up using the stub. Remove the dead code, call the right
method.

Fallout from https://crrev.com/23748d4a10c7a3cefb87851045250b8b86887938

BUG=1110131

Change-Id: I04884f4d86b1a07b56b65bb49711f3b9ca060b69
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2324444Reviewed-by: Mustaq Ahmed <mustaq@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792444}

third_party/blink/renderer/platform/widget/frame_widget.h

@@ -168,7 +168,6 @@ class PLATFORM_EXPORT FrameWidget
   virtual uint64_t GetScrollableContainerIdAt(const gfx::PointF& point) = 0;
 
   virtual bool ShouldHandleImeEvents() { return false; }
-  virtual bool ShouldDispatchImeEventsToPepper() { return false; }
 
   virtual void SetEditCommandsForNextKeyEvent(
       Vector<mojom::blink::EditCommandPtr> edit_commands) = 0;

third_party/blink/renderer/platform/widget/widget_base.cc

@@ -744,7 +744,7 @@ void WidgetBase::ImeSetComposition(
   FrameWidget* frame_widget = client_->FrameWidget();
   if (!frame_widget)
     return;
-  if (frame_widget->ShouldDispatchImeEventsToPepper()) {
+  if (frame_widget->Client()->ShouldDispatchImeEventsToPepper()) {
     frame_widget->Client()->ImeSetCompositionForPepper(
         text,
         std::vector<ui::ImeTextSpan>(ime_text_spans.begin(),
@@ -777,7 +777,7 @@ void WidgetBase::ImeCommitText(const String& text,
   FrameWidget* frame_widget = client_->FrameWidget();
   if (!frame_widget)
     return;
-  if (frame_widget->ShouldDispatchImeEventsToPepper()) {
+  if (frame_widget->Client()->ShouldDispatchImeEventsToPepper()) {
     frame_widget->Client()->ImeCommitTextForPepper(
         text,
         std::vector<ui::ImeTextSpan>(ime_text_spans.begin(),
@@ -801,7 +801,7 @@ void WidgetBase::ImeFinishComposingText(bool keep_selection) {
   FrameWidget* frame_widget = client_->FrameWidget();
   if (!frame_widget)
     return;
-  if (frame_widget->ShouldDispatchImeEventsToPepper()) {
+  if (frame_widget->Client()->ShouldDispatchImeEventsToPepper()) {
     frame_widget->Client()->ImeFinishComposingTextForPepper(keep_selection);
     return;
   }