YouTube videos stop after six seek attempts:We received several reports of YouTube videos failing to play. Many reports indicated that this symptom had something to do with using the slider while playing the video. However, we didn't have a reliable scenario to reproduce in this in-house.Darin Fisher observed that if you move the slider many times, the video stopped playing. Furthermore, he found out that if the slider was moved exactly six times the video would stop playing. This was interesting, because Google Chrome uses a maximum of 6 HTTP connections per host. A quick check of the 'I/O Status' in about:network revealed that all connections were active. The question then became one of why the existing connections weren't canceled when the slider was moved. Darin found that the Flash plugin would return an error when we supplied it data while the slider was moved. In this case a browser is supposed to cancel the connection and that's what fixed it.Google Finance chart dragging:This report was very interesting, due to the fact that it only occurred on single core machines. Of course, in the end we found out that there wasn't any direct connection between the root cause and single core machines. In Google Chrome plugin windows live in a separate plugin process so a plugin has little or no influence on the browser thread, or so we thought.After some inspection we found out that when a plugin is receiving mouse input, the browser main thread spins with 100% CPU for sometime. Now, the twist to the story is that since a plugin window is a child of the browser window, thread inputs of the browser and the plugin are attached. We started looking at the browser message loop more closely. Soon we discovered that MsgWaitForMultipleObjects/PeekMessage APIs behaved strangely when thread inputs are attached. The MsgWaitForMultipleObjects API is typically used to block until an event or a windows message such as an input is available for processing. In this case, we found that it was returning an indication that an input event was available for processing, while PeekMessage indicated no event was available. This behavior is probably due to the fact that thread inputs are attached and GetQueueStatus, called internally by MsgWaitForMultipleObjects, returned an indication that input is available in the browser thread, while in reality it was intended for the plugin. This caused the MsgWaitForMultipleObjects not do its intended function of waiting, and caused the browser thread to spin.