Move ContentViewCore native ownership to WebContents

content/browser/android/content_view_core_impl.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/android/content_view_core_impl.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/android/scoped_java_ref.h"
@@ skipping 47 matching lines @@
 using WebKit::WebInputEventFactory;
 
 // Describes the type and enabled state of a select popup item.
 // Keep in sync with the value defined in SelectPopupDialog.java
 enum PopupItemType {
   POPUP_ITEM_TYPE_GROUP = 0,
   POPUP_ITEM_TYPE_DISABLED,
   POPUP_ITEM_TYPE_ENABLED
 };
 
+namespace content {
+
 namespace {
 jfieldID g_native_content_view;
+
+const void* kContentViewUserDataKey = &kContentViewUserDataKey;
 }  // namespace
 
-namespace content {
+// Enables a callback when the underlying WebContents is destroyed, to enable
+// nulling the back-pointer.
+class ContentViewCoreImpl::ContentViewUserData
+    : public base::SupportsUserData::Data {
+ public:
+  explicit ContentViewUserData(ContentViewCoreImpl* content_view_core)
+      : content_view_core_(content_view_core) {
+  }
+
+  virtual ~ContentViewUserData() {
+    // TODO(joth): When chrome has finished removing the TabContents class (see
+    // crbug.com/107201) consider inverting relationship, so ContentViewCore
+    // would own WebContents. That effectively implies making the WebContents
+    // destructor private on Android.
+    delete content_view_core_;
+  }
+
+  ContentViewCoreImpl* get() const { return content_view_core_; }
+
+ private:
+  // Not using scoped_ptr as ContentViewCoreImpl destructor is private.
+  ContentViewCoreImpl* content_view_core_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ContentViewUserData);
+};
 
 struct ContentViewCoreImpl::JavaObject {
   ScopedJavaGlobalRef<jclass> rect_clazz;
   jmethodID rect_constructor;
 };
 
+// static
+ContentViewCoreImpl* ContentViewCoreImpl::FromWebContents(
+    content::WebContents* web_contents) {
+  ContentViewCoreImpl::ContentViewUserData* data =
+      reinterpret_cast<ContentViewCoreImpl::ContentViewUserData*>(
+          web_contents->GetUserData(kContentViewUserDataKey));
+  return data ? data->get() : NULL;
+}
+
+// static
+ContentViewCore* ContentViewCore::FromWebContents(
+    content::WebContents* web_contents) {
+  return ContentViewCoreImpl::FromWebContents(web_contents);
+}
+
 ContentViewCore* ContentViewCore::GetNativeContentViewCore(JNIEnv* env,
                                                            jobject obj) {
   return reinterpret_cast<ContentViewCore*>(
       env->GetIntField(obj, g_native_content_view));
 }
 
-
 ContentViewCoreImpl::ContentViewCoreImpl(JNIEnv* env, jobject obj,
                                          bool hardware_accelerated,
                                          WebContents* web_contents,
                                          ui::WindowAndroid* window_android)
     : java_ref_(env, obj),
       web_contents_(static_cast<WebContentsImpl*>(web_contents)),
       tab_crashed_(false),
       window_android_(window_android) {
   DCHECK(web_contents) <<
       "A ContentViewCoreImpl should be created with a valid WebContents.";
@@ skipping 16 matching lines @@
   // Currently, the only use case we have for overriding a user agent involves
   // spoofing a desktop Linux user agent for "Request desktop site".
   // Automatically set it for all WebContents so that it is available when a
   // NavigationEntry requires the user agent to be overridden.
   const char kLinuxInfoStr[] = "X11; Linux x86_64";
   std::string product = content::GetContentClient()->GetProduct();
   std::string spoofed_ua =
       webkit_glue::BuildUserAgentFromOSAndProduct(kLinuxInfoStr, product);
   web_contents->SetUserAgentOverride(spoofed_ua);
 
-  InitWebContents(web_contents);
+  InitWebContents();
 }
 
 ContentViewCoreImpl::~ContentViewCoreImpl() {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  ScopedJavaLocalRef<jobject> j_obj = java_ref_.get(env);
+  java_ref_.reset();
+  if (!j_obj.is_null()) {
+    Java_ContentViewCore_onNativeContentViewCoreDestroyed(
+        env, j_obj.obj(), reinterpret_cast<jint>(this));
+  }
   // Make sure nobody calls back into this object while we are tearing things
   // down.
   notification_registrar_.RemoveAll();
 
   delete java_object_;
   java_object_ = NULL;
+}
+
+void ContentViewCoreImpl::OnJavaContentViewCoreDestroyed(JNIEnv* env,
+                                                         jobject obj) {
+  DCHECK(env->IsSameObject(java_ref_.get(env).obj(), obj));
   java_ref_.reset();
 }
 
-void ContentViewCoreImpl::Destroy(JNIEnv* env, jobject obj) {
-  delete this;
-}
-
-void ContentViewCoreImpl::InitWebContents(WebContents* web_contents) {
-  web_contents_ = static_cast<WebContentsImpl*>(web_contents);
+void ContentViewCoreImpl::InitWebContents() {
+  DCHECK(web_contents_);
   notification_registrar_.Add(this,
       NOTIFICATION_RENDER_VIEW_HOST_CHANGED,
       Source<NavigationController>(&web_contents_->GetController()));
 
   static_cast<WebContentsViewAndroid*>(web_contents_->GetView())->
       SetContentViewCore(this);
+  DCHECK(!web_contents_->GetUserData(kContentViewUserDataKey));
+  web_contents_->SetUserData(kContentViewUserDataKey,
+                             new ContentViewUserData(this));
 }
 
 void ContentViewCoreImpl::Observe(int type,
                                   const NotificationSource& source,
                                   const NotificationDetails& details) {
   switch (type) {
     case NOTIFICATION_EXECUTE_JAVASCRIPT_RESULT: {
       if (!web_contents_ || Source<RenderViewHost>(source).ptr() !=
           web_contents_->GetRenderViewHost()) {
         return;
@@ skipping 809 matching lines @@
   if (!HasField(env, clazz, "mNativeContentViewCore", "I")) {
     DLOG(ERROR) << "Unable to find ContentView.mNativeContentViewCore!";
     return false;
   }
   g_native_content_view = GetFieldID(env, clazz, "mNativeContentViewCore", "I");
 
   return RegisterNativesImpl(env) >= 0;
 }
 
 }  // namespace content