Handle WebContents going away in content settings bubbles.

chrome/browser/ui/content_settings/content_setting_bubble_model.cc

Index: chrome/browser/ui/content_settings/content_setting_bubble_model.cc
diff --git a/chrome/browser/ui/content_settings/content_setting_bubble_model.cc b/chrome/browser/ui/content_settings/content_setting_bubble_model.cc
index 525410cd7ac64bbe61a81541991868d353fb70cb..1ac88d4f98ea1e825c7f92483c0147fe9cd4f95f 100644
--- a/chrome/browser/ui/content_settings/content_setting_bubble_model.cc
+++ b/chrome/browser/ui/content_settings/content_setting_bubble_model.cc
@@ -976,7 +976,9 @@ ContentSettingMixedScriptBubbleModel::ContentSettingMixedScriptBubbleModel(
 }
 
 void ContentSettingMixedScriptBubbleModel::OnCustomLinkClicked() {
-  DCHECK(web_contents());
+  if (!web_contents())
+    return;
+
   web_contents()->SendToAllFrames(
       new ChromeViewMsg_SetAllowRunningInsecureContent(MSG_ROUTING_NONE, true));
   web_contents()->GetMainFrame()->Send(new ChromeViewMsg_ReloadFrame(
@@ -1079,6 +1081,9 @@ void ContentSettingRPHBubbleModel::OnRadioClicked(int radio_index) {
 }
 
 void ContentSettingRPHBubbleModel::OnDoneClicked() {
+  if (!web_contents())
+    return;
+
   // The user has one chance to deal with the RPH content setting UI,
   // then we remove it.
   TabSpecificContentSettings::FromWebContents(web_contents())->
@@ -1090,6 +1095,9 @@ void ContentSettingRPHBubbleModel::OnDoneClicked() {
 }
 
 void ContentSettingRPHBubbleModel::RegisterProtocolHandler() {
+  if (!web_contents())
+    return;
+
   // A no-op if the handler hasn't been ignored, but needed in case the user
   // selects sequences like register/ignore/register.
   registry_->RemoveIgnoredHandler(pending_handler_);
@@ -1100,6 +1108,9 @@ void ContentSettingRPHBubbleModel::RegisterProtocolHandler() {
 }
 
 void ContentSettingRPHBubbleModel::UnregisterProtocolHandler() {
+  if (!web_contents())
+    return;
+
   registry_->OnDenyRegisterProtocolHandler(pending_handler_);
   TabSpecificContentSettings::FromWebContents(web_contents())->
       set_pending_protocol_handler_setting(CONTENT_SETTING_BLOCK);
@@ -1107,6 +1118,9 @@ void ContentSettingRPHBubbleModel::UnregisterProtocolHandler() {
 }
 
 void ContentSettingRPHBubbleModel::IgnoreProtocolHandler() {
+  if (!web_contents())
+    return;
+
   registry_->OnIgnoreRegisterProtocolHandler(pending_handler_);
   TabSpecificContentSettings::FromWebContents(web_contents())->
       set_pending_protocol_handler_setting(CONTENT_SETTING_DEFAULT);