Send Mouse Leave events all the time when we get a ET_MOUSE_EXITED

Once we have shipped this for a release this feature flag can be removed.
I've tested Windows and the issues causing the spurious ET_MOUSE_EXITED
don't exist anymore so I believe this is safe to ship in this fashion.

BUG=450631,240300,352106,386896,569998,575208

Review-Url: https://codereview.chromium.org/2618063002
Cr-Commit-Position: refs/heads/master@{#442076}

content/browser/renderer_host/render_widget_host_view_event_handler.cc

@@ -548,7 +548,7 @@ bool RenderWidgetHostViewEventHandler::CanRendererHandleEvent(
   if (event->type() == ui::ET_MOUSE_EXITED) {
     if (mouse_locked || selection_popup)
       return false;
-#if defined(OS_WIN)
+#if defined(OS_WIN) || defined(OS_LINUX)
     // Don't forward the mouse leave message which is received when the context
     // menu is displayed by the page. This confuses the page and causes state
     // changes.

ui/events/blink/blink_features.cc

@@ -11,14 +11,6 @@ namespace features {
 const base::Feature kVsyncAlignedInputEvents{"VsyncAlignedInput",
                                              base::FEATURE_DISABLED_BY_DEFAULT};
 
-const base::Feature kSendMouseLeaveEvents {
-  "SendMouseLeaveEvents",
-// TODO(chaopeng) this fix only for chromeos now, should convert ET_MOUSE_EXITED
-// to MouseLeave when crbug.com/450631 fixed.
-#if defined(OS_CHROMEOS)
-      base::FEATURE_ENABLED_BY_DEFAULT
-#else
-      base::FEATURE_DISABLED_BY_DEFAULT
-#endif
-};
+const base::Feature kSendMouseLeaveEvents{"SendMouseLeaveEvents",
+                                          base::FEATURE_ENABLED_BY_DEFAULT};
 }

ui/events/blink/blink_features.h

@@ -13,8 +13,8 @@ extern const base::Feature kVsyncAlignedInputEvents;
 
 // This feature allows native ET_MOUSE_EXIT events to be passed
 // through to blink as mouse leave events. Traditionally these events were
-// converted to mouse move events due to a number of incosistencies on
-// the native platforms. Enabled by default on ChromeOS. crbug.com/450631
+// converted to mouse move events due to a number of inconsistencies on
+// the native platforms. crbug.com/450631
 extern const base::Feature kSendMouseLeaveEvents;
 }