Fix a crash on Mac due to TextInputManager being null

content/browser/renderer_host/render_widget_host_view_mac.mm

 // 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/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <Carbon/Carbon.h>
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
@@ skipping 546 matching lines @@
   return GetTextInputManager()->GetTextInputState()->type;
 }
 
 RenderWidgetHostImpl* RenderWidgetHostViewMac::GetActiveWidget() {
   return GetTextInputManager() ? GetTextInputManager()->GetActiveWidget()
                                : nullptr;
 }
 
 const TextInputManager::CompositionRangeInfo*
 RenderWidgetHostViewMac::GetCompositionRangeInfo() {
-  return text_input_manager_->GetCompositionRangeInfo();
+  return GetTextInputManager() ? text_input_manager_->GetCompositionRangeInfo()

[EhsanK, 2017/04/10 15:30:39]

This is similar to lines 557 and 561 above. I think this will stop the crash.

+                               : nullptr;
 }
 
 const TextInputManager::TextSelection*
 RenderWidgetHostViewMac::GetTextSelection() {
   return text_input_manager_->GetTextSelection(
       GetFocusedViewForTextSelection());
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewMac, RenderWidgetHostView implementation:
@@ skipping 2929 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end