Don't issue any extra geometry for the IOSurface leak workaround

The official solution to the problem where an IOSurface outlives
its bindings is to send a glBegin/glEnd pair down, which will
kick loose any references in the kernel.

BUG=158469


Review URL: https://chromiumcodereview.appspot.com/11418303

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@170938 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/renderer_host/compositing_iosurface_mac.h

@@ -196,10 +196,6 @@ class CompositingIOSurfaceMac {
                           bool is_vsync_disabled,
                           CVDisplayLinkRef display_link);
 
-  // Issue a draw call to try to flush references to an IOSurface out of
-  // the GL driver.
-  void DoWorkaroundForIOSurfaceLeak();
-
   // Returns true if IOSurface is ready to render. False otherwise.
   bool MapIOSurfaceToTexture(uint64 io_surface_handle);
 

content/browser/renderer_host/compositing_iosurface_mac.mm

@@ -386,11 +386,13 @@ void CompositingIOSurfaceMac::DrawIOSurface(NSView* view, float scale_factor) {
       }
     }
 
-    glUseProgram(0); CHECK_GL_ERROR();
+    // Workaround for issue 158469. Issue a dummy draw call with texture_ not
+    // bound to blit_rgb_sampler_location_, in order to shake all references
+    // to the IOSurface out of the driver.
+    glBegin(GL_TRIANGLES);
+    glEnd();
 
-    // Issue a dummy draw call to flush references to the IOSurface out of
-    // the GL driver.
-    DoWorkaroundForIOSurfaceLeak();
+    glUseProgram(0); CHECK_GL_ERROR();
   } else {
     // Should match the clear color of RenderWidgetHostViewMac.
     glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
@@ -530,34 +532,6 @@ void CompositingIOSurfaceMac::DrawQuad(const SurfaceQuad& quad) {
   glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 }
 
-void CompositingIOSurfaceMac::DoWorkaroundForIOSurfaceLeak() {
-  if (!shader_program_blit_rgb_)
-    return;
-
-  glMatrixMode(GL_PROJECTION);
-  glLoadIdentity();
-  glOrtho(0, 1, 0, 1, -1, 1);
-  glMatrixMode(GL_MODELVIEW);
-  glLoadIdentity();
-
-  // Workaround for issue 158469. Issue a dummy draw call with texture_ not
-  // bound to blit_rgb_sampler_location_, in order to shake all references
-  // to the IOSurface out of the driver.
-  glUseProgram(shader_program_blit_rgb_);
-  glUniform1i(blit_rgb_sampler_location_, 0);
-  glActiveTexture(GL_TEXTURE0 + 0);
-  glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0);
-
-  // Let invisible_quad be a quad that is outside of the viewport.
-  SurfaceQuad invisible_quad;
-  invisible_quad.set_rect(-2.0f, -2.0f, -1.9f, -1.9f);
-  invisible_quad.set_texcoord_rect(0.0f, 0.0f, 1.0f, 1.0f);
-  DrawQuad(invisible_quad);
-  glUseProgram(0);
-
-  CHECK_GL_ERROR();
-}
-
 void CompositingIOSurfaceMac::UnrefIOSurfaceWithContextCurrent() {
   if (texture_) {
     glDeleteTextures(1, &texture_);