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=dalecurtis@chromium.org

Change-Id: Ida89064c5c1c68cf24708d2f6536569812507186
Reviewed-on: https://chromium-review.googlesource.com/924169Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537562}

content/renderer/media/webrtc/rtc_video_decoder.cc

@@ -365,8 +365,8 @@ void RTCVideoDecoder::DismissPictureBuffer(int32_t id) {
 
   if (!picture_buffers_at_display_.count(id)) {
     // We can delete the texture immediately as it's not being displayed.
-    for (const auto& id : buffer_to_dismiss.client_texture_ids())
-      factories_->DeleteTexture(id);
+    for (const auto& texture_id : buffer_to_dismiss.client_texture_ids())
+      factories_->DeleteTexture(texture_id);
     return;
   }
   // Not destroying a texture in display in |picture_buffers_at_display_|.