gpu: Add CHROMIUM_copy_image extension.

ui/gl/gl_image_memory.cc

Index: ui/gl/gl_image_memory.cc
diff --git a/ui/gl/gl_image_memory.cc b/ui/gl/gl_image_memory.cc
index f99dce59fdbfe0dbf0bcb2f85a6c2e67ddc3892a..6c18247505910c00598e9575b69861f5bdedab98 100644
--- a/ui/gl/gl_image_memory.cc
+++ b/ui/gl/gl_image_memory.cc
@@ -12,7 +12,9 @@
 #include "ui/gfx/buffer_format_util.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_context.h"
+#include "ui/gl/gl_fence.h"
 #include "ui/gl/gl_version_info.h"
+#include "ui/gl/scoped_binders.h"
 
 using gfx::BufferFormat;
 
@@ -488,6 +490,35 @@ bool GLImageMemory::CopyTexSubImage(unsigned target,
   return true;
 }
 
+bool GLImageMemory::CopySubImageData(unsigned texture_id,
+                                     const gfx::Point& offset,
+                                     const gfx::Rect& rect,
+                                     GLFence* in_fence,
+                                     GLFence* out_fence) {
+  TRACE_EVENT2("gpu", "GLImageMemory::CopySubImageData", "width", rect.width(),
+               "height", rect.height());
+
+  // Output fence must have support for client side signaling.
+  if (out_fence && !out_fence->SignalSupported())
+    return false;
+
+  if (in_fence)
+    in_fence->ClientWait();
+
+  {
+    ScopedTextureBinder texture_binder(GL_TEXTURE_2D, texture_id);
+
+    bool rv = CopyTexSubImage(GL_TEXTURE_2D, offset, rect);
+    if (!rv)
+      return false;
+  }
+
+  if (out_fence)
+    out_fence->Signal();
+
+  return true;
+}
+
 bool GLImageMemory::ScheduleOverlayPlane(gfx::AcceleratedWidget widget,
                                          int z_order,
                                          gfx::OverlayTransform transform,