[Android] Fix ime NPE after RWH is destroyed

content/browser/renderer_host/ime_adapter_android.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/browser/renderer_host/ime_adapter_android.h"
 
 #include <android/input.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
@@ skipping 122 matching lines @@
                                       time_ms, key_code, unicode_char,
                                       is_system_key);
     char_event.skip_in_browser = key_down_text_insertion;
     rwhva_->SendKeyEvent(char_event);
   }
   return true;
 }
 
 void ImeAdapterAndroid::SetComposingText(JNIEnv* env, jobject, jstring text,
                                          int new_cursor_pos) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   string16 text16 = ConvertJavaStringToUTF16(env, text);
   std::vector<WebKit::WebCompositionUnderline> underlines;
   underlines.push_back(
       WebKit::WebCompositionUnderline(0, text16.length(), SK_ColorBLACK,
                                       false));
   // new_cursor_position is as described in the Android API for
   // InputConnection#setComposingText, whereas the parameters for
   // ImeSetComposition are relative to the start of the composition.
   if (new_cursor_pos > 0)
     new_cursor_pos = text16.length() + new_cursor_pos - 1;
 
   rwhi->ImeSetComposition(text16, underlines, new_cursor_pos, new_cursor_pos);
 }
 
 void ImeAdapterAndroid::ImeBatchStateChanged(JNIEnv* env,
                                              jobject,
                                              jboolean is_begin) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   rwhi->Send(new ViewMsg_ImeBatchStateChanged(rwhi->GetRoutingID(), is_begin));
 }
 
 void ImeAdapterAndroid::CommitText(JNIEnv* env, jobject, jstring text) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   string16 text16 = ConvertJavaStringToUTF16(env, text);
   rwhi->ImeConfirmComposition(text16, ui::Range::InvalidRange(), false);
 }
 
 void ImeAdapterAndroid::FinishComposingText(JNIEnv* env, jobject) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   rwhi->ImeConfirmComposition(string16(), ui::Range::InvalidRange(), true);
 }
 
 void ImeAdapterAndroid::AttachImeAdapter(JNIEnv* env, jobject java_object) {
   java_ime_adapter_ = JavaObjectWeakGlobalRef(env, java_object);
 }
 
 void ImeAdapterAndroid::CancelComposition() {
   base::android::ScopedJavaLocalRef<jobject> obj =
       java_ime_adapter_.get(AttachCurrentThread());
   if (!obj.is_null())
     Java_ImeAdapter_cancelComposition(AttachCurrentThread(), obj.obj());
 }
 
 void ImeAdapterAndroid::SetEditableSelectionOffsets(JNIEnv*, jobject,
                                                     int start, int end) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   rwhi->Send(new ViewMsg_SetEditableSelectionOffsets(rwhi->GetRoutingID(),
                                                      start, end));
 }
 
 void ImeAdapterAndroid::SetComposingRegion(JNIEnv*, jobject,
                                            int start, int end) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   std::vector<WebKit::WebCompositionUnderline> underlines;
   underlines.push_back(
       WebKit::WebCompositionUnderline(0, end - start, SK_ColorBLACK, false));
 
   rwhi->Send(new ViewMsg_SetCompositionFromExistingText(
       rwhi->GetRoutingID(), start, end, underlines));
 }
 
 void ImeAdapterAndroid::DeleteSurroundingText(JNIEnv*, jobject,
                                               int before, int after) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   rwhi->Send(new ViewMsg_ExtendSelectionAndDelete(rwhi->GetRoutingID(),
                                                   before, after));
 }
 
 void ImeAdapterAndroid::Unselect(JNIEnv* env, jobject) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   rwhi->Unselect();
 }
 
 void ImeAdapterAndroid::SelectAll(JNIEnv* env, jobject) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   rwhi->SelectAll();
 }
 
 void ImeAdapterAndroid::Cut(JNIEnv* env, jobject) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   rwhi->Cut();
 }
 
 void ImeAdapterAndroid::Copy(JNIEnv* env, jobject) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   rwhi->Copy();
 }
 
 void ImeAdapterAndroid::Paste(JNIEnv* env, jobject) {
-  RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(
-      rwhva_->GetRenderWidgetHost());
+  RenderWidgetHostImpl* rwhi = GetRenderWidgetHostImpl();
   if (!rwhi)
     return;
 
   rwhi->Paste();
 }
 
 void ImeAdapterAndroid::ResetImeAdapter(JNIEnv* env, jobject) {
   java_ime_adapter_.reset();
 }
 
+RenderWidgetHostImpl* ImeAdapterAndroid::GetRenderWidgetHostImpl() {
+  DCHECK(rwhva_);
+  if (!rwhva_->GetRenderWidgetHost())

[Ben Murdoch, 2013/08/12 10:38:08]

nit: make a local

+    return NULL;
+
+  return RenderWidgetHostImpl::From(rwhva_->GetRenderWidgetHost());
+}
+
 }  // namespace content