Use a single CGLContextObj to draw and update the IOSurface

content/browser/compositor/io_surface_texture_mac.mm

Index: content/browser/compositor/io_surface_texture_mac.mm
diff --git a/content/browser/compositor/io_surface_texture_mac.mm b/content/browser/compositor/io_surface_texture_mac.mm
index dea6b2876828f0d477ab96ebc989fa0985a5341b..545791e13140c39e8fd023d7060d0a8a91c2ddf9 100644
--- a/content/browser/compositor/io_surface_texture_mac.mm
+++ b/content/browser/compositor/io_surface_texture_mac.mm
@@ -35,30 +35,28 @@ namespace content {
 
 // static
 scoped_refptr<IOSurfaceTexture> IOSurfaceTexture::Create() {
-  scoped_refptr<IOSurfaceContext> offscreen_context =
-      IOSurfaceContext::Get(
-          IOSurfaceContext::kOffscreenContext);
-  if (!offscreen_context.get()) {
+  scoped_refptr<IOSurfaceContext> context = IOSurfaceContext::Get();
+  if (!context.get()) {
     LOG(ERROR) << "Failed to create context for offscreen operations";
     return NULL;
   }
 
-  return new IOSurfaceTexture(offscreen_context);
+  return new IOSurfaceTexture(context);
 }
 
 IOSurfaceTexture::IOSurfaceTexture(
-    const scoped_refptr<IOSurfaceContext>& offscreen_context)
-    : offscreen_context_(offscreen_context),
+    const scoped_refptr<IOSurfaceContext>& context)
+    : context_(context),
       texture_(0),
       gl_error_(GL_NO_ERROR),
       eviction_queue_iterator_(eviction_queue_.Get().end()),
       eviction_has_been_drawn_since_updated_(false) {
-  CHECK(offscreen_context_.get());
+  CHECK(context_.get());
 }
 
 IOSurfaceTexture::~IOSurfaceTexture() {
   ReleaseIOSurfaceAndTexture();
-  offscreen_context_ = NULL;
+  context_ = NULL;
   DCHECK(eviction_queue_iterator_ == eviction_queue_.Get().end());
 }
 
@@ -174,7 +172,7 @@ bool IOSurfaceTexture::SetIOSurface(
   CGLError cgl_error = kCGLNoError;
   {
     gfx::ScopedCGLSetCurrentContext scoped_set_current_context(
-        offscreen_context_->cgl_context());
+        context_->cgl_context());
     glGenTextures(1, &texture_);
     glBindTexture(GL_TEXTURE_RECTANGLE_ARB, texture_);
     glTexParameterf(
@@ -182,7 +180,7 @@ bool IOSurfaceTexture::SetIOSurface(
     glTexParameterf(
         GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     cgl_error = CGLTexImageIOSurface2D(
-        offscreen_context_->cgl_context(),
+        context_->cgl_context(),
         GL_TEXTURE_RECTANGLE_ARB,
         GL_RGBA,
         rounded_size.width(),
@@ -211,7 +209,7 @@ bool IOSurfaceTexture::SetIOSurface(
 
 void IOSurfaceTexture::ReleaseIOSurfaceAndTexture() {
   gfx::ScopedCGLSetCurrentContext scoped_set_current_context(
-      offscreen_context_->cgl_context());
+      context_->cgl_context());
 
   if (texture_) {
     glDeleteTextures(1, &texture_);
@@ -223,10 +221,6 @@ void IOSurfaceTexture::ReleaseIOSurfaceAndTexture() {
   EvictionMarkEvicted();
 }
 
-bool IOSurfaceTexture::HasBeenPoisoned() const {
-  return offscreen_context_->HasBeenPoisoned();
-}
-
 GLenum IOSurfaceTexture::GetAndSaveGLError() {
   GLenum gl_error = glGetError();
   if (gl_error_ == GL_NO_ERROR)