Hook up guest browser plugins to the accessibility tree.

content/browser/frame_host/frame_accessibility.cc

+// 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 "content/browser/frame_host/frame_accessibility.h"
+
+#include "content/browser/frame_host/frame_tree.h"
+#include "content/browser/frame_host/frame_tree_node.h"
+#include "content/browser/frame_host/render_frame_host_delegate.h"
+#include "content/browser/frame_host/render_frame_host_impl.h"
+#include "content/public/browser/browser_context.h"
+
+namespace content {
+
+// static
+FrameAccessibility* FrameAccessibility::GetInstance() {
+  return Singleton<FrameAccessibility>::get();
+}
+
+FrameAccessibility::ChildFrameMapping::ChildFrameMapping()
+    : parent_frame_host(NULL),
+      accessibility_node_id(0),
+      child_frame_tree_node_id(0),
+      browser_plugin_instance_id(0) {}
+
+FrameAccessibility::FrameAccessibility() {}
+
+FrameAccessibility::~FrameAccessibility() {}
+
+void FrameAccessibility::AddChildFrame(
+    RenderFrameHostImpl* parent_frame_host,
+    int accessibility_node_id,
+    int64 child_frame_tree_node_id) {
+  for (std::vector<ChildFrameMapping>::iterator iter = mappings_.begin();
+       iter != mappings_.end();
+       ++iter) {
+    // TODO(dmazzoni): the renderer should keep track of these mappings
+    // and clear an existing mapping before setting a new one, that would
+    // be safer than just updating existing mappings. http://crbug.com/413464
+    if (iter->parent_frame_host == parent_frame_host &&
+        (iter->accessibility_node_id == accessibility_node_id ||
+         iter->child_frame_tree_node_id == child_frame_tree_node_id)) {
+      iter->accessibility_node_id = accessibility_node_id;
+      iter->child_frame_tree_node_id = child_frame_tree_node_id;
+      return;
+    }
+  }
+
+  ChildFrameMapping new_mapping;
+  new_mapping.parent_frame_host = parent_frame_host;
+  new_mapping.accessibility_node_id = accessibility_node_id;
+  new_mapping.child_frame_tree_node_id = child_frame_tree_node_id;
+  mappings_.push_back(new_mapping);
+}
+
+void FrameAccessibility::AddGuestWebContents(
+    RenderFrameHostImpl* parent_frame_host,
+    int accessibility_node_id,
+    int browser_plugin_instance_id) {
+  for (std::vector<ChildFrameMapping>::iterator iter = mappings_.begin();
+       iter != mappings_.end();
+       ++iter) {
+    // TODO(dmazzoni): the renderer should keep track of these mappings
+    // and clear an existing mapping before setting a new one, that would
+    // be safer than just updating existing mappings. http://crbug.com/413464
+    if (iter->parent_frame_host == parent_frame_host &&
+        (iter->accessibility_node_id == accessibility_node_id ||
+         iter->browser_plugin_instance_id == browser_plugin_instance_id)) {
+      iter->accessibility_node_id = accessibility_node_id;
+      iter->browser_plugin_instance_id = browser_plugin_instance_id;
+      return;
+    }
+  }
+
+  ChildFrameMapping new_mapping;
+  new_mapping.parent_frame_host = parent_frame_host;
+  new_mapping.accessibility_node_id = accessibility_node_id;
+  new_mapping.browser_plugin_instance_id = browser_plugin_instance_id;
+  mappings_.push_back(new_mapping);
+}
+
+void FrameAccessibility::OnRenderFrameHostDestroyed(
+    RenderFrameHostImpl* render_frame_host) {
+  // Since the order doesn't matter, the fastest way to remove all items
+  // with this render_frame_host is to iterate over the vector backwards,
+  // swapping each one with the back element if we need to delete it.
+  int initial_len = static_cast<int>(mappings_.size());
+  for (int i = initial_len - 1; i >= 0; i--) {
+    if (mappings_[i].parent_frame_host == render_frame_host) {
+      mappings_[i] = mappings_.back();
+      mappings_.pop_back();
+    }
+  }
+}
+
+RenderFrameHostImpl* FrameAccessibility::GetChild(
+    RenderFrameHostImpl* parent_frame_host,
+    int accessibility_node_id) {
+  for (std::vector<ChildFrameMapping>::iterator iter = mappings_.begin();
+       iter != mappings_.end();
+       ++iter) {
+    if (iter->parent_frame_host != parent_frame_host ||
+        iter->accessibility_node_id != accessibility_node_id) {
+      continue;
+    }
+
+    if (iter->child_frame_tree_node_id) {
+      FrameTreeNode* child_node =
+          FrameTree::GloballyFindByID(iter->child_frame_tree_node_id);
+      if (!child_node)
+        return NULL;
+
+      // We should have gotten a node in the same frame tree.
+      DCHECK_EQ(child_node->frame_tree(),
+                parent_frame_host->frame_tree_node()->frame_tree());
+      if (child_node->frame_tree() !=
+              parent_frame_host->frame_tree_node()->frame_tree()) {
+        return NULL;

[Charlie Reis, 2014/09/12 21:01:58]

nit: You can put a NOTREACHED before the return NULL for the same debug-only
effect, without repeating the comparison.

[dmazzoni, 2014/09/15 17:55:23]

Done.

+      }
+
+      return child_node->current_frame_host();
+    }
+
+    if (iter->browser_plugin_instance_id) {
+      RenderFrameHost* guest =
+          parent_frame_host->delegate()->GetGuestByInstanceID(
+              iter->browser_plugin_instance_id);
+      if (guest)
+        return static_cast<RenderFrameHostImpl*>(guest);
+    }
+  }
+
+  return NULL;
+}
+
+bool FrameAccessibility::GetParent(
+    RenderFrameHostImpl* child_frame_host,
+    RenderFrameHostImpl** out_parent_frame_host,
+    int* out_accessibility_node_id) {
+  for (std::vector<ChildFrameMapping>::iterator iter = mappings_.begin();
+       iter != mappings_.end();
+       ++iter) {
+    if (iter->child_frame_tree_node_id) {
+      FrameTreeNode* child_node =
+          FrameTree::GloballyFindByID(iter->child_frame_tree_node_id);
+      if (child_node &&
+          child_node->current_frame_host() == child_frame_host) {
+        // We should have gotten a node in the same frame tree.
+        DCHECK_EQ(child_node->frame_tree(),
+                  iter->parent_frame_host->frame_tree_node()->frame_tree());
+        if (child_node->frame_tree() !=
+                iter->parent_frame_host->frame_tree_node()->frame_tree()) {
+          return false;

[Charlie Reis, 2014/09/12 21:01:58]

NOTREACHED rather than DCHECK with duplicate comparison.

[dmazzoni, 2014/09/15 17:55:23]

Done.

+        }
+
+        if (out_parent_frame_host)
+          *out_parent_frame_host = iter->parent_frame_host;
+        if (out_accessibility_node_id)
+          *out_accessibility_node_id = iter->accessibility_node_id;
+        return true;
+      }
+    }
+
+    if (iter->browser_plugin_instance_id) {
+      RenderFrameHost* guest =
+          iter->parent_frame_host->delegate()->GetGuestByInstanceID(
+              iter->browser_plugin_instance_id);
+      if (guest == child_frame_host) {
+        if (out_parent_frame_host)
+          *out_parent_frame_host = iter->parent_frame_host;
+        if (out_accessibility_node_id)
+          *out_accessibility_node_id = iter->accessibility_node_id;
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+}  // namespace content