Redesigns the text input focus handling.

ui/views/widget/desktop_aura/desktop_native_widget_aura.cc

Index: ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
diff --git a/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc b/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
index 12aec9272d816cc17b93a1f47efd2fb6707d0376..b0e6737d60bd2e936b811f1fea87f37d61be1b6c 100644
--- a/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
+++ b/ui/views/widget/desktop_aura/desktop_native_widget_aura.cc
@@ -15,6 +15,7 @@
 #include "ui/aura/window_property.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/hit_test.h"
+#include "ui/base/ui_base_switches_util.h"
 #include "ui/compositor/layer.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/display.h"
@@ -25,8 +26,8 @@
 #include "ui/views/corewm/tooltip.h"
 #include "ui/views/corewm/tooltip_controller.h"
 #include "ui/views/drag_utils.h"
-#include "ui/views/ime/input_method.h"
 #include "ui/views/ime/input_method_bridge.h"
+#include "ui/views/ime/null_input_method.h"
 #include "ui/views/view_constants_aura.h"
 #include "ui/views/widget/desktop_aura/desktop_capture_client.h"
 #include "ui/views/widget/desktop_aura/desktop_cursor_loader_updater.h"
@@ -629,6 +630,9 @@ bool DesktopNativeWidgetAura::HasCapture() const {
 }
 
 InputMethod* DesktopNativeWidgetAura::CreateInputMethod() {
+  if (switches::IsTextInputFocusManagerEnabled())
+    return new NullInputMethod();
+
   ui::InputMethod* host = input_method_event_filter_->input_method();
   return new InputMethodBridge(this, host, false);
 }
@@ -638,6 +642,10 @@ internal::InputMethodDelegate*
   return this;
 }
 
+ui::InputMethod* DesktopNativeWidgetAura::GetHostInputMethod() {
+  return input_method_event_filter_->input_method();
+}
+
 void DesktopNativeWidgetAura::CenterWindow(const gfx::Size& size) {
   if (content_window_)
     desktop_window_tree_host_->CenterWindow(size);
@@ -1072,16 +1080,26 @@ void DesktopNativeWidgetAura::OnWindowFocused(aura::Window* gained_focus,
     desktop_window_tree_host_->OnNativeWidgetFocus();
     native_widget_delegate_->OnNativeFocus(lost_focus);
 
-    // If focus is moving from a descendant Window to |content_window_| then
-    // native activation hasn't changed. We still need to inform the InputMethod
-    // we've been focused though.
-    InputMethod* input_method = GetWidget()->GetInputMethod();
-    if (input_method)
-      input_method->OnFocus();
+    if (!switches::IsTextInputFocusManagerEnabled()) {
+      // If focus is moving from a descendant Window to |content_window_| then
+      // native activation hasn't changed. We still need to inform the
+      // InputMethod we've been focused though.
+      InputMethod* input_method = GetWidget()->GetInputMethod();
+      if (input_method)
+        input_method->OnFocus();
+    }
+
+    // Ensure the focused view's TextInputClient is used for text input.
+    views::FocusManager* focus_manager = GetWidget()->GetFocusManager();
+    focus_manager->FocusTextInputClient(focus_manager->GetFocusedView());
   } else if (content_window_ == lost_focus) {
     desktop_window_tree_host_->OnNativeWidgetBlur();
     native_widget_delegate_->OnNativeBlur(
         aura::client::GetFocusClient(content_window_)->GetFocusedWindow());
+
+    // Ensure the focused view's TextInputClient is not used for text input.
+    views::FocusManager* focus_manager = GetWidget()->GetFocusManager();
+    focus_manager->BlurTextInputClient(focus_manager->GetFocusedView());
   }
 }