Create a new RenderFrameHost per child frame when --site-per-process is enabled.

content/browser/renderer_host/frame_tree_unittest.cc

+// Copyright (c) 2013 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/frame_tree.h"
+
+#include "base/run_loop.h"
+#include "content/browser/renderer_host/render_frame_host_impl.h"
+#include "content/public/test/mock_render_process_host.h"
+#include "content/public/test/test_browser_context.h"
+#include "content/public/test/test_browser_thread_bundle.h"
+#include "content/public/test/test_renderer_host.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace content {
+namespace {
+
+class FrameTreeTest : public RenderViewHostTestHarness {
+};
+
+// The root node never changes during navigation even though its
+// RenderFrameHost does.
+//  - Swapping main frame doesn't change root node.
+//  - Swapping back to NULL doesn't crash (easier tear-down).
+//  - Main frame does not own RenderFrameHost.
+TEST_F(FrameTreeTest, RootNode) {
+  FrameTree frame_tree;
+
+  // Initial state has empty node.
+  FrameTreeNode* root = frame_tree.GetRootForTesting();
+  ASSERT_TRUE(root);
+  EXPECT_FALSE(frame_tree.GetMainFrame());
+
+  // Swap in main frame.
+  RenderFrameHostImpl* dummy = reinterpret_cast<RenderFrameHostImpl*>(0x1);
+  frame_tree.SwapMainFrame(dummy);
+  EXPECT_EQ(root, frame_tree.GetRootForTesting());
+  EXPECT_EQ(dummy, frame_tree.GetMainFrame());
+
+  // Move back to NULL.

[Charlie Reis, 2013/09/27 19:19:21]

It's not immediately clear why we need to support setting this to null.  Maybe
mention that we do this for interstitials, or otherwise explain why this case is
needed?

[awong, 2013/09/27 20:50:09]

It's in the top level comment.

+  frame_tree.SwapMainFrame(NULL);
+  EXPECT_EQ(root, frame_tree.GetRootForTesting());
+  EXPECT_FALSE(frame_tree.GetMainFrame());
+
+  // Move back to an invalid pointer, let the FrameTree go out of scope. Test
+  // should not crash because the main frame isn't owned.
+  frame_tree.SwapMainFrame(dummy);
+}
+
+// Test swapping of main frame resets the render-assgined frame id.

[Charlie Reis, 2013/09/27 19:19:21]

nit: Test that swapping the main frame
(hard to read as is)

nit: renderer-assigned
(typos in both words)

[awong, 2013/09/27 20:50:09]

Done.

+//  - On creation, frame id is unassigned.
+//  - After a swap, frame id is unassigned.
+TEST_F(FrameTreeTest, FirstNavigationAfterSwap) {
+  FrameTree frame_tree;
+
+  ASSERT_TRUE(frame_tree.IsFirstNavigationAfterSwap());

[Charlie Reis, 2013/09/27 19:19:21]

These should use EXPECT, right?  (ASSERT is for things that set up the testing
scenario and prevent the test from continuing.)

[awong, 2013/09/27 20:50:09]

Good catch. done.

+  frame_tree.OnFirstNavigationAfterSwap(1);
+  ASSERT_FALSE(frame_tree.IsFirstNavigationAfterSwap());
+
+  frame_tree.SwapMainFrame(NULL);
+  ASSERT_TRUE(frame_tree.IsFirstNavigationAfterSwap());

[Charlie Reis, 2013/09/27 19:19:21]

We haven't actually tested anything about the frame ID being assigned or
unassigned, as the test comment describes.  Can you add that?

[awong, 2013/09/27 20:50:09]

Done.

+}
+
+// Exercise tree manipulation routines.
+//   - Add a series of nodes and verify tree structure.

[Charlie Reis, 2013/09/27 19:19:21]

nit: One less indent space, like the comments above.

[awong, 2013/09/27 20:50:09]

Done.

+//   - Remove a series of nodes and verify tree structure.
+TEST_F(FrameTreeTest, Shape) {
+  FrameTree frame_tree;
+  std::string no_children_node("no children node");
+  std::string deep_subtree("node with deep subtree");
+
+  // Ensure the top-level node of the FrameTree is initalized by simulating a

[Charlie Reis, 2013/09/27 19:19:21]

initialized

[awong, 2013/09/27 20:50:09]

Done.

+  // main frame swap here.
+  RenderFrameHostImpl render_frame_host(process(), &frame_tree,
+                                        process()->GetNextRoutingID(), false);
+  frame_tree.SwapMainFrame(&render_frame_host);
+  frame_tree.OnFirstNavigationAfterSwap(5);
+
+  // Let's send a series of messages for frame attached and build the

[Charlie Reis, 2013/09/27 19:19:21]

for frame attached -> to simulate attaching a frame

[awong, 2013/09/27 20:50:09]

rewrote the whole comment.

+  // frame tree.
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 5, 14, std::string());
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 5, 15, std::string());
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 5, 16, std::string());
+
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 14, 244, std::string());
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 14, 245, std::string());
+
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 15, 255, no_children_node);
+
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 16, 264, std::string());
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 16, 265, std::string());
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 16, 266, std::string());
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 16, 267, deep_subtree);
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 16, 268, std::string());
+
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 267, 365, std::string());
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 365, 455, std::string());
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 455, 555, std::string());
+  frame_tree.AddFrame(process()->GetNextRoutingID(), 555, 655, std::string());
+
+  // Now, verify the tree structure is as expected.
+  FrameTreeNode* root = frame_tree.GetRootForTesting();
+  EXPECT_EQ(5, root->frame_id());
+  EXPECT_EQ(3UL, root->child_count());
+
+  EXPECT_EQ(2UL, root->child_at(0)->child_count());
+  EXPECT_EQ(0UL, root->child_at(0)->child_at(0)->child_count());
+  EXPECT_EQ(0UL, root->child_at(0)->child_at(1)->child_count());
+
+  EXPECT_EQ(1UL, root->child_at(1)->child_count());
+  EXPECT_EQ(0UL, root->child_at(1)->child_at(0)->child_count());
+  EXPECT_STREQ(no_children_node.c_str(),
+      root->child_at(1)->child_at(0)->frame_name().c_str());
+
+  EXPECT_EQ(5UL, root->child_at(2)->child_count());
+  EXPECT_EQ(0UL, root->child_at(2)->child_at(0)->child_count());
+  EXPECT_EQ(0UL, root->child_at(2)->child_at(1)->child_count());
+  EXPECT_EQ(0UL, root->child_at(2)->child_at(2)->child_count());
+  EXPECT_EQ(1UL, root->child_at(2)->child_at(3)->child_count());
+  EXPECT_STREQ(deep_subtree.c_str(),
+      root->child_at(2)->child_at(3)->frame_name().c_str());
+  EXPECT_EQ(0UL, root->child_at(2)->child_at(4)->child_count());
+
+  FrameTreeNode* deep_tree = root->child_at(2)->child_at(3)->child_at(0);
+  EXPECT_EQ(365, deep_tree->frame_id());
+  EXPECT_EQ(1UL, deep_tree->child_count());
+  EXPECT_EQ(455, deep_tree->child_at(0)->frame_id());
+  EXPECT_EQ(1UL, deep_tree->child_at(0)->child_count());
+  EXPECT_EQ(555, deep_tree->child_at(0)->child_at(0)->frame_id());
+  EXPECT_EQ(1UL, deep_tree->child_at(0)->child_at(0)->child_count());
+  EXPECT_EQ(655, deep_tree->child_at(0)->child_at(0)->child_at(0)->frame_id());
+  EXPECT_EQ(0UL,
+      deep_tree->child_at(0)->child_at(0)->child_at(0)->child_count());
+
+  // Test removing of nodes.
+  frame_tree.RemoveFrame(555, 655);
+  EXPECT_EQ(0UL, deep_tree->child_at(0)->child_at(0)->child_count());
+
+  frame_tree.RemoveFrame(16, 265);
+  EXPECT_EQ(4UL, root->child_at(2)->child_count());
+
+  frame_tree.RemoveFrame(5, 15);
+  EXPECT_EQ(2UL, root->child_count());
+}
+
+}  // namespace
+}  // namespace content