Do not skip updating composition info on Mac.

content/renderer/render_widget.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_widget.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 1824 matching lines @@
 #if BUILDFLAG(ENABLE_PLUGINS)
   if (focused_pepper_plugin_)
     return focused_pepper_plugin_->text_input_type();
 #endif
   if (auto* controller = GetInputMethodController())
     return ConvertWebTextInputType(controller->TextInputType());
   return ui::TEXT_INPUT_TYPE_NONE;
 }
 
 void RenderWidget::UpdateCompositionInfo(bool immediate_request) {
-  if (!monitor_composition_info_ && !immediate_request)
+#if defined(OS_MACOSX)
+  // On Mac without OOPIF, IME malfunctions if we skip update.

[aelias_OOO_until_Jul13, 2017/05/23 18:14:48]

"On Mac without OOPIF, <webview> IME"

+  // TODO(crbug.com/714771): Remove this platform-specific guard once we have
+  // a proper fix for crbug.com/714771 or we fully launch OOPIF.

[aelias_OOO_until_Jul13, 2017/05/23 18:14:48]

doesn't need "fully launch OOPIF", just "launch OOPIF for <webview>.

+  const bool may_skip_update =
+      base::FeatureList::IsEnabled(::features::kGuestViewCrossProcessFrames);

[aelias_OOO_until_Jul13, 2017/05/23 18:19:25]

Please check that the current renderer is a <webview> tag.  As it is, this
change also affects non-webview on Mac since the feature flag is global, so it
doesn't really address my concern.

ekaramad@, what is the way to check that we're within a webview?

[EhsanK, 2017/05/23 18:39:50]

Yes this is the generic way.

+#else
+  const bool may_skip_update = true;
+#endif
+
+  if (may_skip_update && !monitor_composition_info_ && !immediate_request)
     return;  // Do not calculate composition info if not requested.
 
   TRACE_EVENT0("renderer", "RenderWidget::UpdateCompositionInfo");
   gfx::Range range;
   std::vector<gfx::Rect> character_bounds;
 
   if (GetTextInputType() == ui::TEXT_INPUT_TYPE_NONE) {
     // Composition information is only available on editable node.
     range = gfx::Range::InvalidRange();
   } else {
@@ skipping 485 matching lines @@
     // browser side (https://crbug.com/669219).
     // If there is no WebFrameWidget, then there will be no
     // InputMethodControllers for a WebLocalFrame.
     return nullptr;
   }
   return static_cast<blink::WebFrameWidget*>(GetWebWidget())
       ->GetActiveWebInputMethodController();
 }
 
 }  // namespace content