This is the most important part of the patch series. It removes the
PScreenManager protocol and use ScreenManager directly in the content
processes.
Initial and subsequent updates are sent via PContent::RefreshScreens.
struct ScreenDetails are kept to serialize Screen over IPC.
nsIScreenManager::ScreenForNativeWidget is removed because
nsIWidget::GetWidgetScreen can replace it. nsIScreen::GetId is removed
because it's not useful for the more general Screen class.
MozReview-Commit-ID: 5dJO3isgBuQ
Changes to nsIScreen and nsIScreenManager were reviewed by roc.
Changes to dom/ipc were reviewed by jimm.
Changes to gfx/src/nsDeviceContext.cpp were reviewed by roc.
Changes to widget/android were reviewed by snorp.
Changes to widget/cocoa were reviewed by smichaud.
Changes to widget/gtk were reviewed by roc.
Changes to widget/windows were reviewed by jimm.
Changes to widget/xpwidgets were reviewed by roc.
Changes to nsIScreen and nsIScreenManager were reviewed by roc.
Changes to dom/ipc were reviewed by jimm.
Changes to gfx/src/nsDeviceContext.cpp were reviewed by roc.
Changes to widget/android were reviewed by snorp.
Changes to widget/cocoa were reviewed by smichaud.
Changes to widget/gtk were reviewed by roc.
Changes to widget/windows were reviewed by jimm.
Changes to widget/xpwidgets were reviewed by roc.
