Chrome-side of fixes for content-script messaging.

This change adds registration of content scripts, parented to a frame's
context.  When a frame's context goes away, we unregister it and any content
script contexts for it.

There's a corresponding webkit change that lets us know when a content script
context is created.  Filed upstream as
https://bugs.webkit.org/show_bug.cgi?id=27104.

BUG=16228
TEST=install an extension with a content script that communicates with a parent
process.  Messages should be sendable both ways.

Review URL: http://codereview.chromium.org/155309

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@20677 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 82 insertions, 32 deletions

diff --git a/chrome/renderer/extensions/bindings_utils.h b/chrome/renderer/extensions/bindings_utils.h
index 2e8935a5..2c81b0c 100644
--- a/chrome/renderer/extensions/bindings_utils.h
+++ b/chrome/renderer/extensions/bindings_utils.h
@@ -61,9 +61,15 @@ struct ContextInfo {
   v8::Persistent<v8::Context> context;
   std::string extension_id;  // empty if the context is not an extension
 
+  // If this context is a content script, parent will be the frame that it
+  // was injected in.  This is empty if the context is not a content script.
+  v8::Persistent<v8::Context> parent_context;
+
   ContextInfo(v8::Persistent<v8::Context> context,
-              const std::string& extension_id)
-      : context(context), extension_id(extension_id) {}
+              const std::string& extension_id,
+              v8::Persistent<v8::Context> parent_context)
+      : context(context), extension_id(extension_id),
+        parent_context(parent_context) {}
 };
 typedef std::list< linked_ptr<ContextInfo> > ContextList;
 
diff --git a/chrome/renderer/extensions/event_bindings.cc b/chrome/renderer/extensions/event_bindings.cc
index 03cccad..eab00fc 100644
--- a/chrome/renderer/extensions/event_bindings.cc
+++ b/chrome/renderer/extensions/event_bindings.cc
@@ -118,14 +118,61 @@ RenderThreadBase* EventBindings::GetRenderThread() {
   return render_thread ? render_thread : RenderThread::current();
 }
 
+static void HandleContextDestroyed(ContextList::iterator context_iter) {
+  // Notify the bindings that they're going away.
+  CallFunctionInContext((*context_iter)->context, "dispatchOnUnload", 0, NULL);
+
+  // Remove all pending requests for this context.
+  PendingRequestMap& pending_requests = GetPendingRequestMap();
+  for (PendingRequestMap::iterator it = pending_requests.begin();
+       it != pending_requests.end(); ) {
+    PendingRequestMap::iterator current = it++;
+    if (current->second->context == (*context_iter)->context) {
+      current->second->context.Dispose();
+      current->second->context.Clear();
+      pending_requests.erase(current);
+    }
+  }
+
+  // Unload any content script contexts for this frame.
+  for (ContextList::iterator it = GetContexts().begin();
+       it != GetContexts().end(); ) {
+    ContextList::iterator current = it++;
+    if ((*current)->parent_context == (*context_iter)->context)
+      HandleContextDestroyed(current);
+  }
+
+  // Remove it from our registered contexts.
+  (*context_iter)->context.ClearWeak();
+  (*context_iter)->context.Dispose();
+  (*context_iter)->context.Clear();
+  GetContexts().erase(context_iter);
+}
+
+static void ContextWeakReferenceCallback(v8::Persistent<v8::Value> context,
+                                         void*)
+{
+  for (ContextList::iterator it = GetContexts().begin();
+       it != GetContexts().end(); ++it) {
+    if ((*it)->context == context) {
+      HandleContextDestroyed(it);
+      return;
+    }
+  }
+
+  NOTREACHED();
+}
+
 void EventBindings::HandleContextCreated(WebFrame* frame) {
   if (!bindings_registered)
     return;
 
   v8::HandleScope handle_scope;
-  v8::Local<v8::Context> context = frame->GetScriptContext();
+  ContextList& contexts = GetContexts();
+  v8::Local<v8::Context> frame_context = frame->GetScriptContext();
+  v8::Local<v8::Context> context = v8::Context::GetCurrent();
   DCHECK(!context.IsEmpty());
-  DCHECK(bindings_utils::FindContext(context) == GetContexts().end());
+  DCHECK(bindings_utils::FindContext(context) == contexts.end());
 
   GURL url = frame->GetView()->GetMainFrame()->GetURL();
   std::string extension_id;
@@ -134,8 +181,19 @@ void EventBindings::HandleContextCreated(WebFrame* frame) {
 
   v8::Persistent<v8::Context> persistent_context =
       v8::Persistent<v8::Context>::New(context);
-  GetContexts().push_back(linked_ptr<ContextInfo>(
-      new ContextInfo(persistent_context, extension_id)));
+  v8::Persistent<v8::Context> parent_context;
+
+  if (frame_context != context) {
+    // The new context doesn't belong to the frame: it's a content script.
+    DCHECK(bindings_utils::FindContext(frame_context) != contexts.end());
+    parent_context = v8::Persistent<v8::Context>::New(frame_context);
+    // Content script contexts can get GCed before their frame goes away, so
+    // set up a GC callback.
+    persistent_context.MakeWeak(NULL, &ContextWeakReferenceCallback);
+  }
+
+  contexts.push_back(linked_ptr<ContextInfo>(
+      new ContextInfo(persistent_context, extension_id, parent_context)));
 
   v8::Handle<v8::Value> argv[1];
   argv[0] = v8::String::New(extension_id.c_str());
@@ -151,28 +209,9 @@ void EventBindings::HandleContextDestroyed(WebFrame* frame) {
   v8::Local<v8::Context> context = frame->GetScriptContext();
   DCHECK(!context.IsEmpty());
 
-  ContextList::iterator it = bindings_utils::FindContext(context);
-  DCHECK(it != GetContexts().end());
-
-  // Notify the bindings that they're going away.
-  CallFunctionInContext(context, "dispatchOnUnload", 0, NULL);
-
-  // Remove all pending requests for this context.
-  PendingRequestMap& pending_requests = GetPendingRequestMap();
-  for (PendingRequestMap::iterator it = pending_requests.begin();
-       it != pending_requests.end(); ) {
-    PendingRequestMap::iterator current = it++;
-    if (current->second->context == context) {
-      current->second->context.Dispose();
-      current->second->context.Clear();
-      pending_requests.erase(current);
-    }
-  }
-
-  // Remove it from our registered contexts.
-  (*it)->context.Dispose();
-  (*it)->context.Clear();
-  GetContexts().erase(it);
+  ContextList::iterator context_iter = bindings_utils::FindContext(context);
+  DCHECK(context_iter != GetContexts().end());
+  ::HandleContextDestroyed(context_iter);
 }
 
 // static
diff --git a/chrome/renderer/render_view.cc b/chrome/renderer/render_view.cc
index 012dc3f..436de6e 100644
--- a/chrome/renderer/render_view.cc
+++ b/chrome/renderer/render_view.cc
@@ -1461,14 +1461,18 @@ void RenderView::DocumentElementAvailable(WebFrame* frame) {
         frame, UserScript::DOCUMENT_START);
 }
 
-void RenderView::DidCreateScriptContext(WebFrame* webframe) {
+void RenderView::DidCreateScriptContextForFrame(WebFrame* webframe) {
   EventBindings::HandleContextCreated(webframe);
 }
 
-void RenderView::DidDestroyScriptContext(WebFrame* webframe) {
+void RenderView::DidDestroyScriptContextForFrame(WebFrame* webframe) {
   EventBindings::HandleContextDestroyed(webframe);
 }
 
+void RenderView::DidCreateIsolatedScriptContext(WebFrame* webframe) {
+  EventBindings::HandleContextCreated(webframe);
+}
+
 WindowOpenDisposition RenderView::DispositionForNavigationAction(
     WebView* webview,
     WebFrame* frame,
diff --git a/chrome/renderer/render_view.h b/chrome/renderer/render_view.h
index bf6b6e3..ba6374d 100644
--- a/chrome/renderer/render_view.h
+++ b/chrome/renderer/render_view.h
@@ -218,8 +218,9 @@ class RenderView : public RenderWidget,
 
   virtual void WindowObjectCleared(WebFrame* webframe);
   virtual void DocumentElementAvailable(WebFrame* webframe);
-  virtual void DidCreateScriptContext(WebFrame* webframe);
-  virtual void DidDestroyScriptContext(WebFrame* webframe);
+  virtual void DidCreateScriptContextForFrame(WebFrame* webframe);
+  virtual void DidDestroyScriptContextForFrame(WebFrame* webframe);
+  virtual void DidCreateIsolatedScriptContext(WebFrame* webframe);
 
   virtual WindowOpenDisposition DispositionForNavigationAction(
       WebView* webview,