Fix shadowed variables in the content layer.

Shadowed variables can make code harder to read. Don't support them
in the content layer.

BUG=794619

This CL was uploaded by git cl split.

R=paulmeyer@chromium.org

Change-Id: I0151100128e83c9746375ad898dac8bfc1a89e0e
Reviewed-on: https://chromium-review.googlesource.com/923345Reviewed-by: Paul Meyer <paulmeyer@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537359}

content/browser/find_request_manager.cc

@@ -33,10 +33,10 @@ std::vector<FrameTreeNode*> GetChildren(FrameTreeNode* node) {
   for (size_t i = 0; i != node->child_count(); ++i)
     children[i] = node->child_at(i);
 
-  if (auto* inner_contents = WebContentsImpl::FromOuterFrameTreeNode(node)) {
-    children.push_back(inner_contents->GetMainFrame()->frame_tree_node());
+  if (auto* contents = WebContentsImpl::FromOuterFrameTreeNode(node)) {
+    children.push_back(contents->GetMainFrame()->frame_tree_node());
   } else {
-    auto* contents = WebContentsImpl::FromFrameTreeNode(node);
+    contents = WebContentsImpl::FromFrameTreeNode(node);
     if (node->IsMainFrame() && contents->GetBrowserPluginEmbedder()) {
       for (auto* inner_contents : contents->GetInnerWebContents()) {
         children.push_back(inner_contents->GetMainFrame()->frame_tree_node());