Implement TextureImageTransportSurface using texture mailbox

content/common/gpu/client/gl_helper.cc

Index: content/common/gpu/client/gl_helper.cc
diff --git a/content/common/gpu/client/gl_helper.cc b/content/common/gpu/client/gl_helper.cc
index 645ee436dd392c94277cda4cd1b449b34a594a93..88436958b06bbfedbb99b6e342643e00666af9b2 100644
--- a/content/common/gpu/client/gl_helper.cc
+++ b/content/common/gpu/client/gl_helper.cc
@@ -17,6 +17,7 @@
 #include "base/threading/thread_restrictions.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebCString.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
+#include "third_party/skia/include/core/SkRegion.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
 #include "ui/gl/gl_bindings.h"
@@ -791,4 +792,30 @@ void GLHelper::InitCopyTextToImpl() {
 
 }
 
+void GLHelper::CopySubBufferDamage(WebKit::WebGLId texture,
+                                   WebKit::WebGLId previous_texture,
+                                   const SkRegion& new_damage,
+                                   const SkRegion& old_damage) {
+  SkRegion region(old_damage);
+  if (region.op(new_damage, SkRegion::kDifference_Op)) {
+    ScopedFramebuffer dst_framebuffer(context_, context_->createFramebuffer());
+    ScopedFramebufferBinder<GL_FRAMEBUFFER> framebuffer_binder(
+        context_, dst_framebuffer);
+    ScopedTextureBinder<GL_TEXTURE_2D> texture_binder(context_, texture);
+    context_->framebufferTexture2D(GL_FRAMEBUFFER,
+                                   GL_COLOR_ATTACHMENT0,
+                                   GL_TEXTURE_2D,
+                                   previous_texture,
+                                   0);
+    for (SkRegion::Iterator it(region); !it.done(); it.next()) {
+      const SkIRect& rect = it.rect();
+      context_->copyTexSubImage2D(GL_TEXTURE_2D, 0,
+                                  rect.x(), rect.y(),
+                                  rect.x(), rect.y(),
+                                  rect.width(), rect.height());
+    }
+    context_->flush();
+  }
+}
+
 }  // namespace content