"To achieve the streamlined feel we were after … we had our own intuitions about what was and wasn't useful in current browsers, we had no idea how those ideas matched to reality. So in typical Google fashion, we turned to data; we ran long studies of the browsing habits of thousands of volunteers, compiled giant charts of what features people did and didn't use, argued over and incorporated that data into our designs and prototypes, ran experiments, watched how our test users reacted, listened to their feedback, and then repeated the cycle over and over and over again."
Many Tab OverflowWe don't have a complete system for handling many open tabs right now. We let tabs grow infinitely smaller. This ends up looking bad when there are a very large number of tabs open. We chose not to go with an overflow menu or scrolling tab strip like in some other browsers because we think there are other usability problems with those approaches. Specifically, when you implement an overflow solution you generally pick a minimum "readable" width for the tab and overflow tabs when there are too many at that width to fit. The problem is usually that that width seems to be too wide, so there can be unnecessary overflow in conditions where a smaller tab width would have meant all of the tabs would have fit. We also don't really like the drop-down menu approach as it has a spatial disconnect (vertical scanning vs. horizontal tabs) that makes it clumsy to use quickly. In the end, we would like a system that doesn't over-zealously clip tabs out of the tab strip so that people with many tabs can still access their tabs with one click.Disoriented Anchor TabsOpening tabs next to the tab that opened them can mean for some use cases that the behavior of having a few "anchor" tabs positioned at the left edge of the strip is more difficult since tabs opened from them are opened in between. We like the idea of "tab pinning" or "locking" as a solution for this, but haven't invested a lot of time in designing how this might work just yet. There may be some overlap with "startup tabs" in Options.Restoring Mistakenly Closed WindowsWe also don't prompt when you close a window with several tabs. The reason we don't do this is that one of our core design philosophies has been to avoid modal question prompts that interrupt the user when they're trying to get things done (in this case, use a standard window control to close the window). We're aware that the prompt has saved people (including ourselves!) using other browsers from losing tabs, but we have been trying to come up with a more creative system for helping this scenario that doesn't interfere with the window's close button. In recent trunk builds, you'll find that you can re-open a recently closed window from the New Tab Page, and that the "Recently Closed" section of the New Tab Page now spans multiple sessions. This is a good way to "undo" an accidentally closed window, in the same way you can "undo" an accidentally closed tab. To try this out you can get on the Google Chrome Dev Channel.
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.