[XProto] Remove dependencies on dri2, present, and xf86vidmode

This is a partial revert of 7e489781.
It turns out removing GLX is not necessary since it's already
dynamically loaded.  Using GLX allows us to remove dependencies on
dri2, present, and xf86vidmode.

R=sunnyps

Bug: 1066670
Change-Id: I44b79b06de76a043f38dfd9270eee980134a7816
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2523661Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825100}

ui/gl/gl_surface_glx.cc

@@ -26,12 +26,6 @@
 #include "ui/base/x/x11_util.h"
 #include "ui/events/platform/platform_event_source.h"
 #include "ui/gfx/native_widget_types.h"
-#include "ui/gfx/x/connection.h"
-#include "ui/gfx/x/dri2.h"
-#include "ui/gfx/x/glx.h"
-#include "ui/gfx/x/present.h"
-#include "ui/gfx/x/xf86vidmode.h"
-#include "ui/gfx/x/xproto.h"
 #include "ui/gfx/x/xproto_util.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_context.h"
@@ -103,8 +97,8 @@ bool CreateDummyWindow(x11::Connection* conn) {
 
 class OMLSyncControlVSyncProvider : public SyncControlVSyncProvider {
  public:
-  explicit OMLSyncControlVSyncProvider(x11::Window window)
-      : SyncControlVSyncProvider(), window_(window) {}
+  explicit OMLSyncControlVSyncProvider(GLXWindow glx_window)
+      : SyncControlVSyncProvider(), glx_window_(glx_window) {}
 
   ~OMLSyncControlVSyncProvider() override = default;
 
@@ -112,85 +106,30 @@ class OMLSyncControlVSyncProvider : public SyncControlVSyncProvider {
   bool GetSyncValues(int64_t* system_time,
                      int64_t* media_stream_counter,
                      int64_t* swap_buffer_counter) override {
-    auto* connection = x11::Connection::Get();
-
-    // First try to get the counter values using the DRI2 extension.
-    if (auto reply = connection->dri2().GetMSC({window_}).Sync()) {
-      auto merge_counter = [](uint32_t hi, uint32_t lo) {
-        return (static_cast<uint64_t>(hi) << 32) | lo;
-      };
-      *system_time = merge_counter(reply->ust_hi, reply->ust_lo);
-      *media_stream_counter = merge_counter(reply->msc_hi, reply->msc_lo);
-      *swap_buffer_counter = merge_counter(reply->sbc_hi, reply->sbc_lo);
-      return true;
-    }
-
-    // Next try the present extension.
-    auto& present = connection->present();
-    // Check if the present extension is available.
-    if (!present.present())
-      return false;
-
-    // Issue a NotifyMSC request and listen for the resulting event which will
-    // contain the counter values.
-    auto context = connection->GenerateId<x11::Present::Event>();
-    present.SelectInput(
-        {context, window_, x11::Present::EventMask::CompleteNotify});
-    connection->present().NotifyMSC({window_});
-    present.SelectInput({context, window_, x11::Present::EventMask::NoEvent});
-    connection->Sync();
-    connection->ReadResponses();
-    for (const auto& event : connection->events()) {
-      auto* complete = event.As<x11::Present::CompleteNotifyEvent>();
-      if (complete && complete->kind == x11::Present::CompleteKind::NotifyMSC &&
-          complete->window == window_ && complete->serial == 0) {
-        *system_time = complete->ust;
-        *media_stream_counter = complete->msc;
-        *swap_buffer_counter = 0;
-        return true;
-      }
-    }
-
-    return false;
+    return glXGetSyncValuesOML(x11::Connection::Get()->GetXlibDisplay(),
+                               glx_window_, system_time, media_stream_counter,
+                               swap_buffer_counter);
   }
 
   bool GetMscRate(int32_t* numerator, int32_t* denominator) override {
     if (!g_glx_get_msc_rate_oml_supported)
       return false;
 
-    auto* connection = x11::Connection::Get();
-    connection->xf86vidmode().SetClientVersion(
-        {x11::XF86VidMode::major_version, x11::XF86VidMode::minor_version});
-    auto reply = connection->xf86vidmode()
-                     .GetModeLine({connection->DefaultScreenId()})
-                     .Sync();
-    if (!reply) {
-      // Once GetModeLine has been found to fail, don't try again,
+    if (!glXGetMscRateOML(x11::Connection::Get()->GetXlibDisplay(), glx_window_,
+                          numerator, denominator)) {
+      // Once glXGetMscRateOML has been found to fail, don't try again,
       // since each failing call may spew an error message.
       g_glx_get_msc_rate_oml_supported = false;
       return false;
     }
 
-    *numerator = static_cast<uint32_t>(reply->dotclock) * 1000;
-    *denominator = static_cast<uint32_t>(reply->vtotal) * reply->htotal;
-
-    // These adjustments are from mesa's __glxGetMscRate().
-    if (static_cast<bool>(reply->flags &
-                          x11::XF86VidMode::ModeFlag::Interlace)) {
-      *numerator *= 2;
-    }
-    if (static_cast<bool>(reply->flags &
-                          x11::XF86VidMode::ModeFlag::Composite_Sync)) {
-      *denominator *= 2;
-    }
-
     return true;
   }
 
   bool IsHWClock() const override { return true; }
 
  private:
-  x11::Window window_;
+  GLXWindow glx_window_;
 
   DISALLOW_COPY_AND_ASSIGN(OMLSyncControlVSyncProvider);
 };
@@ -718,7 +657,7 @@ bool NativeViewGLSurfaceGLX::Initialize(GLSurfaceFormat format) {
 
   if (g_glx_oml_sync_control_supported) {
     vsync_provider_ = std::make_unique<OMLSyncControlVSyncProvider>(
-        static_cast<x11::Window>(window_));
+        static_cast<GLXWindow>(glx_window_));
     presentation_helper_ =
         std::make_unique<GLSurfacePresentationHelper>(vsync_provider_.get());
   } else if (g_glx_sgi_video_sync_supported) {