For sending NOTIFY_IME_OF_COMPOSITION_EVENT_HANDLED after the other change notifications which was caused by the user input, we need to use IMEContentObserver::IMENotificationSender because it sends the notifications when it's safe to do it.
This patch makes TextComposition use IMEContentObserver to send the notification. However, if there is no active IMEContentObserver, e.g., composition events are fired on unfocused window, TextComposition sends it by itself (same as current implementation).
If IMEContentObserver stops observing when it has pending NOTIFY_IME_OF_COMPOSITION_EVENT_HANDLED, it cannot send the notification (i.e., it is discarded completely in such case). However, in such case, IMEContentObserver sends NOTIFY_IME_OF_BLUR. So, anyway, native IME handler should treat the blur notification as it including NOTIFY_IME_OF_COMPOSITION_EVENT_HANDLED.
On the other hand, we're buggy if composition events are fired in non-active window. Even in such case, IMEContentObserver should be created for active editor in each document and it notifies IME of the changes. But this is out of the scope of this bug.
MozReview-Commit-ID: 7Q0ZsJTh4hX
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extra : rebase_source : 6417f991fa8c0fbe3f25b27bacf4257e5485aecc
PuppetWidget::GetInputContext() needs to communicate with its parent process with synchronous IPC. This is very expensive for focus move.
Currently, IMEStateManager uses nsIWidget::GetInputContext() only for checking the IME enabled state. Therefore, it's enough to cache input context when nsIWidget::SetInputContext() is called. Then, we can avoid to communicate with synchronous IPC with PuppetWidget::GetInputContext() in most cases.
This patch makes IMEStateManager stores the last widget which sets input context. When PuppetWidget uses its input context cache, it should check if it is the last widget to set input context with IMEStateManager since an input context may be shared with other widgets and another one may have update the input context. I.e., PuppetWidget's input context cache may be already outdated after IMEStateManager sets input context with another widget.
This patch gives up to support retrieving IME open state from child process. However, perhaps, this is not necessary for everybody including add-on developers because the only user of IME open state in child process is nsIDOMWindowUtils. So, add-ons can send IME open state from chrome process instead. If this decision is wrong, unfortunately, we should support it again in another bug. It's easy to support with creating another nsIWidget::GetInputContext() or adding additional argument to it.
MozReview-Commit-ID: B2d2CCTsPKj
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extra : rebase_source : 4117330ba7871753176da960063b612e96f11752
