gpu: fix CopyTextureCHROMIUM for immutable texture.

gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc

Index: gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc b/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc
index ffb9370bca76f071a1a3619a96e9a858007bafda..49bba9b49de15d8c691c0c5a99253c2555b7b22e 100644
--- a/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc
+++ b/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc
@@ -218,7 +218,6 @@ void DoCopyTexImage2D(const gpu::gles2::GLES2Decoder* decoder,
                       GLuint source_id,
                       GLuint dest_id,
                       GLint dest_level,
-                      GLenum dest_internal_format,
                       GLsizei width,
                       GLsizei height,
                       GLuint framebuffer) {
@@ -231,14 +230,8 @@ void DoCopyTexImage2D(const gpu::gles2::GLES2Decoder* decoder,
     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glCopyTexImage2D(GL_TEXTURE_2D,
-                     dest_level,
-                     dest_internal_format,
-                     0 /* x */,
-                     0 /* y */,
-                     width,
-                     height,
-                     0 /* border */);
+    glCopyTexSubImage2D(GL_TEXTURE_2D, dest_level, 0 /* xoffset */,
+                        0 /* yoffset */, 0 /* x */, 0 /* y */, width, height);
   }
 
   decoder->RestoreTextureState(source_id);
@@ -332,16 +325,15 @@ void CopyTextureCHROMIUMResourceManager::DoCopyTexture(
   bool source_format_contain_superset_of_dest_format =
       source_internal_format == dest_internal_format ||
       (source_internal_format == GL_RGBA && dest_internal_format == GL_RGB);
-  // GL_TEXTURE_RECTANGLE_ARB on FBO is supported by OpenGL, not GLES2,
-  // so restrict this to GL_TEXTURE_2D.
-  if (source_target == GL_TEXTURE_2D && !flip_y && !premultiply_alpha_change &&
+  bool source_target_allowed = source_target == GL_TEXTURE_2D ||
+                               source_target == GL_TEXTURE_RECTANGLE_ARB;
+  if (source_target_allowed && !flip_y && !premultiply_alpha_change &&
       source_format_contain_superset_of_dest_format) {
     DoCopyTexImage2D(decoder,
                      source_target,
                      source_id,
                      dest_id,
                      dest_level,
-                     dest_internal_format,
                      width,
                      height,
                      framebuffer_);