Make the GPU process use an X11 event loop

ui/gl/gl_surface_glx.cc

Index: ui/gl/gl_surface_glx.cc
diff --git a/ui/gl/gl_surface_glx.cc b/ui/gl/gl_surface_glx.cc
index 8b705dfbe93751c899daa05752cc585d64229097..89bb09fbce2a33d3207a62456bbb903849ea9800 100644
--- a/ui/gl/gl_surface_glx.cc
+++ b/ui/gl/gl_surface_glx.cc
@@ -14,6 +14,7 @@ extern "C" {
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
+#include "base/message_loop/message_pump_x11.h"
 #include "base/synchronization/cancellation_flag.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/non_thread_safe.h"
@@ -315,7 +316,10 @@ bool GLSurfaceGLX::InitializeOneOff() {
   // it's own thread.
   XInitThreads();
 
-  g_display = base::MessagePumpForUI::GetDefaultXDisplay();
+  // XXX -- base::MessagePumpForUI is returning Gtk here -- we need to
+  // make this *not* be a compile-time decision.
+  g_display = //base::MessagePumpForUI::GetDefaultXDisplay();
+      base::MessagePumpX11::GetDefaultXDisplay();
   if (!g_display) {
     LOG(ERROR) << "XOpenDisplay failed.";
     return false;
@@ -388,31 +392,84 @@ void* GLSurfaceGLX::GetDisplay() {
 
 GLSurfaceGLX::~GLSurfaceGLX() {}
 
+// XXX - we should just have 1 of these, not 1 per GLSurfaceGLX
+class NativeViewXExposeEventForwarder : public base::MessageLoop::Observer {
+ public:
+  NativeViewXExposeEventForwarder(gfx::AcceleratedWidget parent_window,
+                                  gfx::AcceleratedWidget child_window)
+    : child_window_(child_window), parent_window_(parent_window) {
+    base::MessageLoopForUI::current()->AddObserver(this);
+  }
+  ~NativeViewXExposeEventForwarder() {
+    base::MessageLoopForUI::current()->RemoveObserver(this);
+  }
+
+  virtual base::EventStatus WillProcessEvent(
+      const base::NativeEvent& xevent) OVERRIDE {
+    if (xevent->type == Expose &&
+        xevent->xexpose.window == child_window_) {
+      XEvent forwarded_event = *xevent;
+      forwarded_event.xexpose.window = parent_window_;
+      XSendEvent(
+          g_display, parent_window_, False, ExposureMask, &forwarded_event);
+    }
+    return base::EVENT_CONTINUE;
+  }
+  virtual void DidProcessEvent(const base::NativeEvent&) OVERRIDE {
+  }
+
+ private:
+  gfx::AcceleratedWidget child_window_;
+  gfx::AcceleratedWidget parent_window_;
+};
+
 NativeViewGLSurfaceGLX::NativeViewGLSurfaceGLX(gfx::AcceleratedWidget window)
-  : window_(window),
+  : parent_window_(window),
+    window_(0),
     config_(NULL) {
 }
 
 bool NativeViewGLSurfaceGLX::Initialize() {
   XWindowAttributes attributes;
-  if (!XGetWindowAttributes(g_display, window_, &attributes)) {
-    LOG(ERROR) << "XGetWindowAttributes failed for window " << window_ << ".";
+  if (!XGetWindowAttributes(g_display, parent_window_, &attributes)) {
+    LOG(ERROR) << "XGetWindowAttributes failed for window "
+               << parent_window_ << ".";
     return false;
   }
   size_ = gfx::Size(attributes.width, attributes.height);
 
+  XSetWindowAttributes set_attributes = {0};
+  set_attributes.event_mask = ExposureMask;
+  window_= XCreateWindow(
+      g_display, parent_window_, 0, 0, attributes.width, attributes.height, 0,
+      attributes.depth, InputOutput, attributes.visual, CWEventMask,
+      &set_attributes);
+  XMapWindow(g_display, window_);
+  XFlush(g_display);
+
   if (g_glx_oml_sync_control_supported)
     vsync_provider_.reset(new OMLSyncControlVSyncProvider(window_));
   else if (g_glx_sgi_video_sync_supported)
     vsync_provider_.reset(new SGIVideoSyncVSyncProvider(window_));
 
+  event_forwarder_.reset(
+      new NativeViewXExposeEventForwarder(parent_window_, window_));
+
   return true;
 }
 
 void NativeViewGLSurfaceGLX::Destroy() {
+  event_forwarder_.reset();
+  if (window_) {
+    XDestroyWindow(g_display, window_);
+    XFlush(g_display);
+    window_ = 0;
+  }
 }
 
 bool NativeViewGLSurfaceGLX::Resize(const gfx::Size& size) {
+  XResizeWindow(g_display, window_, size.width(), size.height());
+  XFlush(g_display);
   size_ = size;
   return true;
 }
@@ -516,7 +573,8 @@ VSyncProvider* NativeViewGLSurfaceGLX::GetVSyncProvider() {
 }
 
 NativeViewGLSurfaceGLX::NativeViewGLSurfaceGLX()
-  : window_(0),
+  : parent_window_(0),
+    window_(0),
     config_(NULL) {
 }