Adds a frame based test for html_viewer

I'm making the test code use mandoline/tab as that dramatically
simplifies things, and lets me test that code too.

I'm also creating a testing interface for HTMLViewer. It's only
available if a command line flag is supplied. For now it's simple, but
I'm going to add more to it (such as injecting JS).

BUG=479172,490221
TEST=mostly test change
R=ben@chromium.org

Review URL: https://codereview.chromium.org/1210323002

Cr-Commit-Position: refs/heads/master@{#336668}

21 files changed, 410 insertions, 29 deletions

diff --git a/components/html_viewer/BUILD.gn b/components/html_viewer/BUILD.gn
index cbcc4c1..17757ffc64 100644
--- a/components/html_viewer/BUILD.gn
+++ b/components/html_viewer/BUILD.gn
@@ -88,6 +88,8 @@ source_set("lib") {
     "media_factory.h",
     "mock_web_blob_registry_impl.cc",
     "mock_web_blob_registry_impl.h",
+    "test_html_viewer_impl.cc",
+    "test_html_viewer_impl.h",
     "touch_handler.cc",
     "touch_handler.h",
     "web_clipboard_impl.cc",
@@ -121,6 +123,7 @@ source_set("lib") {
     "//components/clipboard/public/interfaces",
     "//components/devtools_service/public/cpp",
     "//components/devtools_service/public/interfaces",
+    "//components/html_viewer/public/interfaces",
     "//components/message_port",
     "//components/mime_util",
     "//components/resource_provider/public/cpp",
@@ -223,11 +226,14 @@ mojo_native_application("apptests") {
 
   sources = [
     "ax_provider_apptest.cc",
+    "html_frame_apptest.cc",
   ]
 
   deps = [
     "//base",
+    "//components/html_viewer/public/interfaces",
     "//components/view_manager/public/cpp/tests:test_support",
+    "//mandoline/tab",
     "//mandoline/tab/public/interfaces",
     "//mojo/application/public/cpp:test_support",
     "//net:test_support",
diff --git a/components/html_viewer/DEPS b/components/html_viewer/DEPS
index 6a70ad0..64e3c45 100644
--- a/components/html_viewer/DEPS
+++ b/components/html_viewer/DEPS
@@ -45,4 +45,8 @@ specific_include_rules = {
   "run_all_unittests\.cc": [
     "+third_party/mojo/src/mojo/edk/embedder/test_embedder.h",
   ],
+  "html_frame_apptest\.cc": [
+    "+mandoline/tab",
+    "+third_party/mojo/src/mojo/edk/embedder/test_embedder.h",
+  ],
 }
diff --git a/components/html_viewer/ax_provider_impl.h b/components/html_viewer/ax_provider_impl.h
index 45582f2..18634cc 100644
--- a/components/html_viewer/ax_provider_impl.h
+++ b/components/html_viewer/ax_provider_impl.h
@@ -5,6 +5,7 @@
 #ifndef COMPONENTS_HTML_VIEWER_AX_PROVIDER_IMPL_H_
 #define COMPONENTS_HTML_VIEWER_AX_PROVIDER_IMPL_H_
 
+#include "base/basictypes.h"
 #include "third_party/mojo/src/mojo/public/cpp/bindings/binding.h"
 #include "third_party/mojo_services/src/accessibility/public/interfaces/accessibility.mojom.h"
 
@@ -35,6 +36,8 @@ class AxProviderImpl : public mojo::AxProvider {
 
   blink::WebView* web_view_;
   mojo::Binding<mojo::AxProvider> binding_;
+
+  DISALLOW_COPY_AND_ASSIGN(AxProviderImpl);
 };
 
 }  // namespace html_viewer
diff --git a/components/html_viewer/frame_tree_manager.cc b/components/html_viewer/frame_tree_manager.cc
index 170bd5b..98d8947 100644
--- a/components/html_viewer/frame_tree_manager.cc
+++ b/components/html_viewer/frame_tree_manager.cc
@@ -120,6 +120,10 @@ blink::WebLocalFrame* FrameTreeManager::GetLocalWebFrame() {
   return GetLocalFrame()->web_frame()->toWebLocalFrame();
 }
 
+blink::WebView* FrameTreeManager::GetWebView() {
+  return root_->web_view();
+}
+
 void FrameTreeManager::InitFrames(mojo::View* local_view, Frame* frame) {
   frame->Init(local_view);
 
diff --git a/components/html_viewer/frame_tree_manager.h b/components/html_viewer/frame_tree_manager.h
index 0a613cc..ef13e7da 100644
--- a/components/html_viewer/frame_tree_manager.h
+++ b/components/html_viewer/frame_tree_manager.h
@@ -66,6 +66,8 @@ class FrameTreeManager : public mandoline::FrameTreeClient {
   Frame* GetLocalFrame();
   blink::WebLocalFrame* GetLocalWebFrame();
 
+  blink::WebView* GetWebView();
+
  private:
   friend class Frame;
 
diff --git a/components/html_viewer/html_document_oopif.cc b/components/html_viewer/html_document_oopif.cc
index 9bd2ab6..1dfc61b 100644
--- a/components/html_viewer/html_document_oopif.cc
+++ b/components/html_viewer/html_document_oopif.cc
@@ -17,6 +17,7 @@
 #include "components/html_viewer/frame.h"
 #include "components/html_viewer/frame_tree_manager.h"
 #include "components/html_viewer/global_state.h"
+#include "components/html_viewer/test_html_viewer_impl.h"
 #include "components/html_viewer/web_url_loader_impl.h"
 #include "components/view_manager/ids.h"
 #include "components/view_manager/public/cpp/view.h"
@@ -36,6 +37,13 @@ using mojo::View;
 namespace html_viewer {
 namespace {
 
+const char kEnableTestInterface[] = "enable-html-viewer-test-interface";
+
+bool IsTestInterfaceEnabled() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      kEnableTestInterface);
+}
+
 bool EnableRemoteDebugging() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       devtools_service::kRemoteDebuggingPort);
@@ -43,6 +51,14 @@ bool EnableRemoteDebugging() {
 
 }  // namespace
 
+HTMLDocumentOOPIF::BeforeLoadCache::BeforeLoadCache() {
+}
+
+HTMLDocumentOOPIF::BeforeLoadCache::~BeforeLoadCache() {
+  STLDeleteElements(&ax_provider_requests);
+  STLDeleteElements(&test_interface_requests);
+}
+
 HTMLDocumentOOPIF::HTMLDocumentOOPIF(mojo::ApplicationImpl* html_document_app,
                                      mojo::ApplicationConnection* connection,
                                      mojo::URLResponsePtr response,
@@ -62,6 +78,10 @@ HTMLDocumentOOPIF::HTMLDocumentOOPIF(mojo::ApplicationImpl* html_document_app,
       static_cast<mojo::InterfaceFactory<mandoline::FrameTreeClient>*>(this));
   connection->AddService(static_cast<InterfaceFactory<AxProvider>*>(this));
   connection->AddService(&view_manager_client_factory_);
+  if (IsTestInterfaceEnabled()) {
+    connection->AddService(
+        static_cast<mojo::InterfaceFactory<TestHTMLViewer>*>(this));
+  }
 
   resource_waiter_.reset(
       new DocumentResourceWaiter(global_state_, response.Pass(), this));
@@ -93,7 +113,6 @@ HTMLDocumentOOPIF::~HTMLDocumentOOPIF() {
   delete_callback_.Run(this);
 
   STLDeleteElements(&ax_providers_);
-  STLDeleteElements(&ax_provider_requests_);
 }
 
 void HTMLDocumentOOPIF::LoadIfNecessary() {
@@ -153,6 +172,13 @@ void HTMLDocumentOOPIF::Load() {
   frame_tree_manager_->GetLocalWebFrame()->loadRequest(web_request);
 }
 
+HTMLDocumentOOPIF::BeforeLoadCache* HTMLDocumentOOPIF::GetBeforeLoadCache() {
+  CHECK(!did_finish_local_frame_load_);
+  if (!before_load_cache_.get())
+    before_load_cache_.reset(new BeforeLoadCache);
+  return before_load_cache_.get();
+}
+
 void HTMLDocumentOOPIF::OnEmbed(View* root) {
   // We're an observer until the document is loaded.
   root->AddObserver(this);
@@ -184,30 +210,54 @@ bool HTMLDocumentOOPIF::ShouldNavigateLocallyInMainFrame() {
 
 void HTMLDocumentOOPIF::OnFrameDidFinishLoad(Frame* frame) {
   // TODO(msw): Notify AxProvider clients of updates on child frame loads.
-  if (frame != frame_tree_manager_->GetLocalFrame())
+  if (frame_tree_manager_ &&
+      frame != frame_tree_manager_->GetLocalFrame()) {
     return;
+  }
 
-  did_finish_main_frame_load_ = true;
+  did_finish_local_frame_load_ = true;
+  scoped_ptr<BeforeLoadCache> before_load_cache = before_load_cache_.Pass();
+  if (!before_load_cache)
+    return;
 
-  // Bind any pending AxProviderImpl interface requests.
-  for (auto it : ax_provider_requests_)
-    ax_providers_.insert(new AxProviderImpl(frame->web_view(), it->Pass()));
-  STLDeleteElements(&ax_provider_requests_);
+  // Bind any pending AxProvider and TestHTMLViewer interface requests.
+  for (auto it : before_load_cache->ax_provider_requests) {
+    ax_providers_.insert(
+        new AxProviderImpl(frame_tree_manager_->GetWebView(), it->Pass()));
+  }
+  for (auto it : before_load_cache->test_interface_requests) {
+    CHECK(IsTestInterfaceEnabled());
+    test_html_viewers_.push_back(new TestHTMLViewerImpl(
+        frame_tree_manager_->GetLocalWebFrame(), it->Pass()));
+  }
 }
 
 void HTMLDocumentOOPIF::Create(mojo::ApplicationConnection* connection,
                                mojo::InterfaceRequest<AxProvider> request) {
-  if (!did_finish_main_frame_load_) {
+  if (!did_finish_local_frame_load_) {
     // Cache AxProvider interface requests until the document finishes loading.
     auto cached_request = new mojo::InterfaceRequest<AxProvider>();
     *cached_request = request.Pass();
-    ax_provider_requests_.insert(cached_request);
+    GetBeforeLoadCache()->ax_provider_requests.insert(cached_request);
   } else {
     ax_providers_.insert(new AxProviderImpl(
         frame_tree_manager_->GetLocalFrame()->web_view(), request.Pass()));
   }
 }
 
+void HTMLDocumentOOPIF::Create(mojo::ApplicationConnection* connection,
+                               mojo::InterfaceRequest<TestHTMLViewer> request) {
+  CHECK(IsTestInterfaceEnabled());
+  if (!did_finish_local_frame_load_) {
+    auto cached_request = new mojo::InterfaceRequest<TestHTMLViewer>();
+    *cached_request = request.Pass();
+    GetBeforeLoadCache()->test_interface_requests.insert(cached_request);
+  } else {
+    test_html_viewers_.push_back(new TestHTMLViewerImpl(
+        frame_tree_manager_->GetLocalWebFrame(), request.Pass()));
+  }
+}
+
 void HTMLDocumentOOPIF::Create(
     mojo::ApplicationConnection* connection,
     mojo::InterfaceRequest<mandoline::FrameTreeClient> request) {
diff --git a/components/html_viewer/html_document_oopif.h b/components/html_viewer/html_document_oopif.h
index 5e9db3f..176317e 100644
--- a/components/html_viewer/html_document_oopif.h
+++ b/components/html_viewer/html_document_oopif.h
@@ -10,8 +10,10 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
 #include "components/html_viewer/ax_provider_impl.h"
 #include "components/html_viewer/frame_tree_manager_delegate.h"
+#include "components/html_viewer/public/interfaces/test_html_viewer.mojom.h"
 #include "components/view_manager/public/cpp/view_manager_client_factory.h"
 #include "components/view_manager/public/cpp/view_manager_delegate.h"
 #include "components/view_manager/public/cpp/view_observer.h"
@@ -39,6 +41,7 @@ class DocumentResourceWaiter;
 class Frame;
 class FrameTreeManager;
 class GlobalState;
+class TestHTMLViewerImpl;
 class WebLayerTreeViewImpl;
 
 // A view for a single HTML document.
@@ -51,7 +54,8 @@ class HTMLDocumentOOPIF
       public mojo::ViewObserver,
       public FrameTreeManagerDelegate,
       public mojo::InterfaceFactory<mojo::AxProvider>,
-      public mojo::InterfaceFactory<mandoline::FrameTreeClient> {
+      public mojo::InterfaceFactory<mandoline::FrameTreeClient>,
+      public mojo::InterfaceFactory<TestHTMLViewer> {
  public:
   using DeleteCallback = base::Callback<void(HTMLDocumentOOPIF*)>;
 
@@ -71,11 +75,23 @@ class HTMLDocumentOOPIF
  private:
   friend class DocumentResourceWaiter;  // So it can call LoadIfNecessary().
 
+  // Requests for interfaces before the document is loaded go here. Once
+  // loaded the requests are bound and BeforeLoadCache is deleted.
+  struct BeforeLoadCache {
+    BeforeLoadCache();
+    ~BeforeLoadCache();
+
+    std::set<mojo::InterfaceRequest<mojo::AxProvider>*> ax_provider_requests;
+    std::set<mojo::InterfaceRequest<TestHTMLViewer>*> test_interface_requests;
+  };
+
   ~HTMLDocumentOOPIF() override;
 
   void LoadIfNecessary();
   void Load();
 
+  BeforeLoadCache* GetBeforeLoadCache();
+
   // ViewManagerDelegate:
   void OnEmbed(mojo::View* root) override;
   void OnViewManagerDestroyed(mojo::ViewManager* view_manager) override;
@@ -100,17 +116,22 @@ class HTMLDocumentOOPIF
       mojo::ApplicationConnection* connection,
       mojo::InterfaceRequest<mandoline::FrameTreeClient> request) override;
 
+  // mojo::InterfaceFactory<TestHTMLViewer>:
+  void Create(mojo::ApplicationConnection* connection,
+              mojo::InterfaceRequest<TestHTMLViewer> request) override;
+
   scoped_ptr<mojo::AppRefCount> app_refcount_;
   mojo::ApplicationImpl* html_document_app_;
   mojo::ApplicationConnection* connection_;
   mojo::ViewManagerClientFactory view_manager_client_factory_;
 
   // HTMLDocument owns these pointers; binding requests after document load.
-  std::set<mojo::InterfaceRequest<mojo::AxProvider>*> ax_provider_requests_;
   std::set<AxProviderImpl*> ax_providers_;
 
-  // A flag set on didFinishLoad.
-  bool did_finish_main_frame_load_ = false;
+  ScopedVector<TestHTMLViewerImpl> test_html_viewers_;
+
+  // Set to true when the local frame has finished loading.
+  bool did_finish_local_frame_load_ = false;
 
   GlobalState* global_state_;
 
@@ -122,6 +143,8 @@ class HTMLDocumentOOPIF
 
   scoped_ptr<DocumentResourceWaiter> resource_waiter_;
 
+  scoped_ptr<BeforeLoadCache> before_load_cache_;
+
   DeleteCallback delete_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(HTMLDocumentOOPIF);
diff --git a/components/html_viewer/html_frame_apptest.cc b/components/html_viewer/html_frame_apptest.cc
new file mode 100644
index 0000000..85109f58
--- /dev/null
+++ b/components/html_viewer/html_frame_apptest.cc
@@ -0,0 +1,157 @@
+// Copyright 2015 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 "base/bind.h"
+#include "base/command_line.h"
+#include "base/run_loop.h"
+#include "base/strings/stringprintf.h"
+#include "base/test/test_timeouts.h"
+#include "components/html_viewer/public/interfaces/test_html_viewer.mojom.h"
+#include "components/view_manager/public/cpp/tests/view_manager_test_base.h"
+#include "components/view_manager/public/cpp/view.h"
+#include "components/view_manager/public/cpp/view_manager.h"
+#include "mandoline/tab/frame.h"
+#include "mandoline/tab/frame_connection.h"
+#include "mandoline/tab/frame_tree.h"
+#include "mandoline/tab/public/interfaces/frame_tree.mojom.h"
+#include "mojo/application/public/cpp/application_impl.h"
+#include "net/test/spawned_test_server/spawned_test_server.h"
+#include "third_party/mojo_services/src/accessibility/public/interfaces/accessibility.mojom.h"
+
+using mandoline::Frame;
+using mandoline::FrameConnection;
+using mandoline::FrameTree;
+using mandoline::FrameTreeClient;
+
+namespace mojo {
+
+namespace {
+
+// Switch to enable out of process iframes.
+const char kOOPIF[] = "oopifs";
+
+bool EnableOOPIFs() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(kOOPIF);
+}
+
+std::string GetFrameText(ApplicationConnection* connection) {
+  html_viewer::TestHTMLViewerPtr test_html_viewer;
+  connection->ConnectToService(&test_html_viewer);
+  std::string result;
+  test_html_viewer->GetContentAsText(
+      [&result](const String& mojo_string) { result = mojo_string; });
+  test_html_viewer.WaitForIncomingResponse();
+  return result;
+}
+
+}  // namespace
+
+class HTMLFrameTest : public ViewManagerTestBase {
+ public:
+  HTMLFrameTest() {}
+  ~HTMLFrameTest() override {}
+
+ protected:
+  mojo::URLRequestPtr BuildRequestForURL(const std::string& url_string) {
+    const uint16_t assigned_port = http_server_->host_port_pair().port();
+    mojo::URLRequestPtr request(mojo::URLRequest::New());
+    request->url = mojo::String::From(
+        base::StringPrintf(url_string.c_str(), assigned_port));
+    return request.Pass();
+  }
+
+  FrameConnection* InitFrameTree(View* view, const std::string& url_string) {
+    scoped_ptr<FrameConnection> frame_connection(new FrameConnection);
+    FrameConnection* result = frame_connection.get();
+    ViewManagerClientPtr view_manager_client;
+    frame_connection->Init(application_impl(), BuildRequestForURL(url_string),
+                           &view_manager_client);
+    FrameTreeClient* frame_tree_client = frame_connection->frame_tree_client();
+    frame_tree_.reset(new FrameTree(view, nullptr, frame_tree_client,
+                                    frame_connection.Pass()));
+    view->Embed(view_manager_client.Pass());
+    return result;
+  }
+
+  bool WaitForEmbedForDescendant() {
+    if (embed_run_loop_)
+      return false;
+    embed_run_loop_.reset(new base::RunLoop);
+    embed_run_loop_->Run();
+    embed_run_loop_.reset();
+    return true;
+  }
+
+  // ViewManagerTest:
+  void SetUp() override {
+    ViewManagerTestBase::SetUp();
+
+    // Make it so we get OnEmbedForDescendant().
+    window_manager()->SetEmbedRoot();
+
+    // Start a test server.
+    http_server_.reset(new net::SpawnedTestServer(
+        net::SpawnedTestServer::TYPE_HTTP, net::SpawnedTestServer::kLocalhost,
+        base::FilePath(FILE_PATH_LITERAL("components/test/data/html_viewer"))));
+    ASSERT_TRUE(http_server_->Start());
+  }
+  void TearDown() override {
+    frame_tree_.reset();
+    http_server_.reset();
+    ViewManagerTestBase::TearDown();
+  }
+  void OnEmbedForDescendant(View* view,
+                            URLRequestPtr request,
+                            ViewManagerClientPtr* client) override {
+    Frame* frame = Frame::FindFirstFrameAncestor(view);
+    scoped_ptr<FrameConnection> frame_connection(new FrameConnection);
+    frame_connection->Init(application_impl(), request.Pass(), client);
+    FrameTreeClient* frame_tree_client = frame_connection->frame_tree_client();
+    frame_tree_->CreateOrReplaceFrame(frame, view, frame_tree_client,
+                                      frame_connection.Pass());
+    if (embed_run_loop_)
+      embed_run_loop_->Quit();
+  }
+
+  scoped_ptr<net::SpawnedTestServer> http_server_;
+  scoped_ptr<FrameTree> frame_tree_;
+
+ private:
+  // A runloop specifically for OnEmbedForDescendant(). We use a separate
+  // runloop here as it's possible at the time OnEmbedForDescendant() is invoked
+  // a separate RunLoop is already running that we shouldn't quit.
+  scoped_ptr<base::RunLoop> embed_run_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(HTMLFrameTest);
+};
+
+TEST_F(HTMLFrameTest, HelloWorld) {
+  if (!EnableOOPIFs())
+    return;
+
+  View* embed_view = window_manager()->CreateView();
+
+  FrameConnection* root_connection = InitFrameTree(
+      embed_view, "http://127.0.0.1:%u/files/page_with_single_frame.html");
+
+  ASSERT_EQ("Page with single frame",
+            GetFrameText(root_connection->application_connection()));
+
+  // page_with_single_frame contains a child frame. The child frame should
+  // create
+  // a new View and Frame.
+  if (embed_view->children().empty())
+    ASSERT_TRUE(WaitForEmbedForDescendant());
+
+  ASSERT_EQ(1u, embed_view->children().size());
+  Frame* child_frame =
+      frame_tree_->root()->FindFrame(embed_view->children()[0]->id());
+  ASSERT_TRUE(child_frame);
+
+  ASSERT_EQ("child",
+            GetFrameText(static_cast<FrameConnection*>(child_frame->user_data())
+                             ->application_connection()));
+}
+
+}  // namespace mojo
diff --git a/components/html_viewer/public/interfaces/BUILD.gn b/components/html_viewer/public/interfaces/BUILD.gn
new file mode 100644
index 0000000..504c103
--- /dev/null
+++ b/components/html_viewer/public/interfaces/BUILD.gn
@@ -0,0 +1,11 @@
+# Copyright 2014 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.
+
+import("//third_party/mojo/src/mojo/public/tools/bindings/mojom.gni")
+
+mojom("interfaces") {
+  sources = [
+    "test_html_viewer.mojom",
+  ]
+}
diff --git a/components/html_viewer/public/interfaces/test_html_viewer.mojom b/components/html_viewer/public/interfaces/test_html_viewer.mojom
new file mode 100644
index 0000000..f2a6b8d
--- /dev/null
+++ b/components/html_viewer/public/interfaces/test_html_viewer.mojom
@@ -0,0 +1,9 @@
+// Copyright 2014 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.
+
+module html_viewer;
+
+interface TestHTMLViewer {
+  GetContentAsText() => (string contents);
+};
diff --git a/components/html_viewer/test_html_viewer_impl.cc b/components/html_viewer/test_html_viewer_impl.cc
new file mode 100644
index 0000000..d403959
--- /dev/null
+++ b/components/html_viewer/test_html_viewer_impl.cc
@@ -0,0 +1,30 @@
+// Copyright 2014 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 "components/html_viewer/test_html_viewer_impl.h"
+
+#include "third_party/WebKit/public/platform/WebString.h"
+#include "third_party/WebKit/public/web/WebDocument.h"
+#include "third_party/WebKit/public/web/WebFrame.h"
+
+using blink::WebDocument;
+using blink::WebFrame;
+
+namespace html_viewer {
+
+TestHTMLViewerImpl::TestHTMLViewerImpl(
+    blink::WebFrame* web_frame,
+    mojo::InterfaceRequest<TestHTMLViewer> request)
+    : web_frame_(web_frame), binding_(this, request.Pass()) {
+}
+
+TestHTMLViewerImpl::~TestHTMLViewerImpl() {
+}
+
+void TestHTMLViewerImpl::GetContentAsText(
+    const GetContentAsTextCallback& callback) {
+  callback.Run(web_frame_->document().contentAsTextForTesting().utf8());
+}
+
+}  // namespace html_viewer
diff --git a/components/html_viewer/test_html_viewer_impl.h b/components/html_viewer/test_html_viewer_impl.h
new file mode 100644
index 0000000..05cc17d
--- /dev/null
+++ b/components/html_viewer/test_html_viewer_impl.h
@@ -0,0 +1,37 @@
+// Copyright 2015 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.
+
+#ifndef COMPONENTS_HTML_VIEWER_TEST_HTML_VIEWER_IMPL_H_
+#define COMPONENTS_HTML_VIEWER_TEST_HTML_VIEWER_IMPL_H_
+
+#include "base/basictypes.h"
+#include "components/html_viewer/public/interfaces/test_html_viewer.mojom.h"
+#include "third_party/mojo/src/mojo/public/cpp/bindings/binding.h"
+
+namespace blink {
+class WebFrame;
+}
+
+namespace html_viewer {
+
+// Caller must ensure that |web_frame| outlives TestHTMLViewerImpl.
+class TestHTMLViewerImpl : public TestHTMLViewer {
+ public:
+  TestHTMLViewerImpl(blink::WebFrame* web_frame,
+                     mojo::InterfaceRequest<TestHTMLViewer> request);
+  ~TestHTMLViewerImpl() override;
+
+ private:
+  // TestHTMLViewer:
+  void GetContentAsText(const GetContentAsTextCallback& callback) override;
+
+  blink::WebFrame* web_frame_;
+  mojo::Binding<TestHTMLViewer> binding_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestHTMLViewerImpl);
+};
+
+}  // namespace html_viewer
+
+#endif  // COMPONENTS_HTML_VIEWER_TEST_HTML_VIEWER_IMPL_H_
diff --git a/components/test/data/html_viewer/empty_page.html b/components/test/data/html_viewer/empty_page.html
new file mode 100644
index 0000000..a5786ef
--- /dev/null
+++ b/components/test/data/html_viewer/empty_page.html
@@ -0,0 +1,5 @@
+<html>
+  <body style="background-color: red">
+    child
+  </body>
+</html>
diff --git a/components/test/data/html_viewer/page_with_single_frame.html b/components/test/data/html_viewer/page_with_single_frame.html
new file mode 100644
index 0000000..cbca1f9
--- /dev/null
+++ b/components/test/data/html_viewer/page_with_single_frame.html
@@ -0,0 +1,7 @@
+<html>
+  <body style="background-color: blue">
+     <iframe width="50%" height="50%"
+     src="empty_page.html"></iframe>
+  Page with single frame
+  </body>
+</html>
diff --git a/mandoline/tab/frame.cc b/mandoline/tab/frame.cc
index e987697..78a781e 100644
--- a/mandoline/tab/frame.cc
+++ b/mandoline/tab/frame.cc
@@ -45,7 +45,7 @@ Frame::Frame(FrameTree* tree,
       view_(view),
       parent_(nullptr),
       view_ownership_(view_ownership),
-      frame_user_data_(user_data.Pass()),
+      user_data_(user_data.Pass()),
       frame_tree_client_(frame_tree_client),
       frame_tree_server_binding_(this) {
   view_->SetLocalProperty(kFrame, this);
@@ -101,6 +101,13 @@ const Frame* Frame::FindFrame(uint32_t id) const {
   return nullptr;
 }
 
+bool Frame::HasAncestor(const Frame* frame) const {
+  const Frame* current = this;
+  while (current && current != frame)
+    current = current->parent_;
+  return current == frame;
+}
+
 void Frame::BuildFrameTree(std::vector<const Frame*>* frames) const {
   frames->push_back(this);
   for (const Frame* frame : children_)
diff --git a/mandoline/tab/frame.h b/mandoline/tab/frame.h
index cd81d20..7b97aaf 100644
--- a/mandoline/tab/frame.h
+++ b/mandoline/tab/frame.h
@@ -39,7 +39,7 @@ class Frame : public mojo::ViewObserver, public FrameTreeServer {
   void Init(Frame* parent);
 
   // Walks the View tree starting at |view| going up returning the first
-  // Frame that is associated with a view. For example, if |view|
+  // Frame that is associated with |view|. For example, if |view|
   // has a Frame associated with it, then that is returned. Otherwise
   // this checks view->parent() and so on.
   static Frame* FindFirstFrameAncestor(mojo::View* view);
@@ -58,7 +58,9 @@ class Frame : public mojo::ViewObserver, public FrameTreeServer {
   }
   const Frame* FindFrame(uint32_t id) const;
 
-  FrameUserData* user_data();
+  bool HasAncestor(const Frame* frame) const;
+
+  FrameUserData* user_data() { return user_data_.get(); }
 
  private:
   friend class FrameTree;
@@ -88,7 +90,7 @@ class Frame : public mojo::ViewObserver, public FrameTreeServer {
   Frame* parent_;
   ViewOwnership view_ownership_;
   std::vector<Frame*> children_;
-  scoped_ptr<FrameUserData> frame_user_data_;
+  scoped_ptr<FrameUserData> user_data_;
 
   FrameTreeClient* frame_tree_client_;
 
diff --git a/mandoline/tab/frame_tree.cc b/mandoline/tab/frame_tree.cc
index b833a590..cba1757 100644
--- a/mandoline/tab/frame_tree.cc
+++ b/mandoline/tab/frame_tree.cc
@@ -35,4 +35,24 @@ Frame* FrameTree::CreateAndAddFrame(mojo::View* view,
   return frame;
 }
 
+Frame* FrameTree::CreateOrReplaceFrame(Frame* frame,
+                                       mojo::View* view,
+                                       FrameTreeClient* frame_tree_client,
+                                       scoped_ptr<FrameUserData> user_data) {
+  DCHECK(frame && frame->HasAncestor(&root_));
+
+  Frame* parent = frame;
+  if (frame->view() == view) {
+    DCHECK(frame != &root_);
+    // Rembed in existing frame.
+    parent = frame->parent();
+    delete frame;
+    frame = nullptr;
+  }  // else case is a view is becoming associated with a Frame, eg a new frame.
+
+  DCHECK(parent);
+
+  return CreateAndAddFrame(view, parent, frame_tree_client, user_data.Pass());
+}
+
 }  // namespace mandoline
diff --git a/mandoline/tab/frame_tree.h b/mandoline/tab/frame_tree.h
index 6d21698..3dc491e6 100644
--- a/mandoline/tab/frame_tree.h
+++ b/mandoline/tab/frame_tree.h
@@ -35,6 +35,15 @@ class FrameTree {
                            FrameTreeClient* client,
                            scoped_ptr<FrameUserData> user_data);
 
+  // If frame->view() == |view|, then |frame| is deleted and a new Frame created
+  // to replace it. Otherwise a new Frame is created as a child of |frame|.
+  // It is expected this is called from
+  //  ViewManagerDelegate::OnEmbedForDescendant().
+  Frame* CreateOrReplaceFrame(Frame* frame,
+                              mojo::View* view,
+                              FrameTreeClient* frame_tree_client,
+                              scoped_ptr<FrameUserData> user_data);
+
  private:
   friend class Frame;
 
diff --git a/mandoline/tab/frame_tree_delegate.h b/mandoline/tab/frame_tree_delegate.h
index f35a89e..9b12aa3 100644
--- a/mandoline/tab/frame_tree_delegate.h
+++ b/mandoline/tab/frame_tree_delegate.h
@@ -7,6 +7,7 @@
 
 namespace mandoline {
 
+class Frame;
 class MessageEvent;
 
 class FrameTreeDelegate {
diff --git a/mandoline/ui/browser/browser.cc b/mandoline/ui/browser/browser.cc
index 96424fd..3cdd52d 100644
--- a/mandoline/ui/browser/browser.cc
+++ b/mandoline/ui/browser/browser.cc
@@ -115,7 +115,8 @@ void Browser::OnEmbedForDescendant(mojo::View* view,
                                    mojo::ViewManagerClientPtr* client) {
   // TODO(sky): move this to Frame/FrameTree.
   Frame* frame = Frame::FindFirstFrameAncestor(view);
-  if (!frame) {
+  if (!frame || !frame->HasAncestor(frame_tree_->root()) ||
+      frame == frame_tree_->root()) {
     // TODO(sky): add requestor url so that we can return false if it's not
     // an app we expect.
     mojo::ApplicationConnection* connection =
@@ -124,19 +125,11 @@ void Browser::OnEmbedForDescendant(mojo::View* view,
     return;
   }
 
-  Frame* parent = frame;
-  if (frame->view() == view) {
-    parent = frame->parent();
-    // This is a reembed.
-    delete frame;
-    frame = nullptr;
-  }
-
   scoped_ptr<FrameConnection> frame_connection(new FrameConnection);
   frame_connection->Init(app_, request.Pass(), client);
   FrameTreeClient* frame_tree_client = frame_connection->frame_tree_client();
-  frame_tree_->CreateAndAddFrame(view, parent, frame_tree_client,
-                                 frame_connection.Pass());
+  frame_tree_->CreateOrReplaceFrame(frame, view, frame_tree_client,
+                                    frame_connection.Pass());
 }
 
 void Browser::OnViewManagerDestroyed(mojo::ViewManager* view_manager) {
diff --git a/mojo/tools/data/apptests b/mojo/tools/data/apptests
index a664220..5043d5d 100644
--- a/mojo/tools/data/apptests
+++ b/mojo/tools/data/apptests
@@ -57,7 +57,8 @@ if config.target_os != config.OS_ANDROID:
     {
       "test": "mojo:html_viewer_apptests",
       "type": "gtest_isolated",
-      "args": ["--use-test-config", "--oopifs"]
+      "args": ["--use-test-config", "--oopifs",
+               "--enable-html-viewer-test-interface"]
     },
     {
       "test": "mojo:mandoline_frame_apptests",