build: move libcc patches to electron repo (#14104)

In the GN build, libchromiumcontent is no longer a distinct library, but
merely a container for a set of scripts and patches. Maintaining those
patches in a separate repository is tedious and error-prone, so merge
them into the main repo.

Once this is merged and GN is the default way to build Electron, the
libchromiumcontent repository can be archived.

patches/common/chromium/enable_osr_components.patch

@@ -0,0 +1,21 @@
+diff --git a/content/browser/renderer_host/input/mouse_wheel_phase_handler.h b/content/browser/renderer_host/input/mouse_wheel_phase_handler.h
+index 4f7c03d62930..25b74d9b5236 100644
+--- a/content/browser/renderer_host/input/mouse_wheel_phase_handler.h
++++ b/content/browser/renderer_host/input/mouse_wheel_phase_handler.h
+@@ -7,6 +7,7 @@
+ 
+ #include "base/timer/timer.h"
+ #include "content/browser/renderer_host/render_widget_host_delegate.h"
++#include "content/common/content_export.h"
+ #include "content/public/common/input_event_ack_state.h"
+ #include "third_party/blink/public/platform/web_mouse_wheel_event.h"
+ 
+@@ -55,7 +56,7 @@ enum class FirstScrollUpdateAckState {
+ // The MouseWheelPhaseHandler is responsible for adding the proper phase to
+ // wheel events. Phase information is necessary for wheel scrolling since it
+ // shows the start and end of a scrolling sequence.
+-class MouseWheelPhaseHandler {
++class CONTENT_EXPORT MouseWheelPhaseHandler {
+  public:
+   MouseWheelPhaseHandler(RenderWidgetHostViewBase* const host_view);
+   ~MouseWheelPhaseHandler() {}