Confirm the compostion text on TAP gesture.

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index 339fec9359479b8e4d1c9ffaf578260748595c82..c65266ef7ee1cd848d317db98c9ae1be4eb4f31d 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -1744,6 +1744,11 @@ void RenderWidgetHostViewAndroid::RunAckCallbacks() {
 
 void RenderWidgetHostViewAndroid::OnGestureEvent(
     const ui::GestureEventData& gesture) {
+  // Confirm existing composition text on TAP gesture, to make sure the input
+  // caret won't be moved with an ongoing composition text.
+  if (gesture.type() == ui::ET_GESTURE_TAP)
+    FinishImeCompositionSession();
+
   blink::WebGestureEvent web_gesture =
       CreateWebGestureEventFromGestureEventData(gesture);
   // TODO(jdduke): Remove this workaround after Android fixes UiAutomator to
@@ -1928,6 +1933,16 @@ void RenderWidgetHostViewAndroid::OnStylusSelectTap(base::TimeTicks time,
   SendGestureEvent(long_press);
 }
 
+void RenderWidgetHostViewAndroid::FinishImeCompositionSession() {
+  if (!ime_adapter_android_.HasComposition())
+    return;
+  if (host_) {
+    host_->ImeConfirmComposition(base::string16(), gfx::Range::InvalidRange(),

[aurimas (slooooooooow), 2015/03/19 05:40:30]

This will get called even if the user taps inside the same input field, so
composition will be cancelled even when user tries to move the carrot within the
same word. That is not a correct behavior compared to Android's EditText, it
keeps the composition unless cursor moves outside of a single word.

Since we do not know where tap is going to land or if the tap is going to be
preventDefaulted, I don't think we can do it in the browser. This should really
be handled somewhere in the renderer.

+                                 false);
+  }
+  ImeCancelComposition();
+}
+
 // static
 void RenderWidgetHostViewBase::GetDefaultScreenInfo(
     blink::WebScreenInfo* results) {