cc: Fix the format of GpuMemoryBuffer for SurfaceTexture

cc/trees/layer_tree_settings.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TREES_LAYER_TREE_SETTINGS_H_
 #define CC_TREES_LAYER_TREE_SETTINGS_H_
 
+#include <vector>
+
 #include "base/basictypes.h"
 #include "cc/base/cc_export.h"
 #include "cc/debug/layer_tree_debug_state.h"
 #include "cc/output/renderer_settings.h"
 #include "cc/scheduler/scheduler_settings.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace cc {
 
@@ skipping 52 matching lines @@
   size_t max_tiles_for_interest_area;
   float skewport_target_time_in_seconds;
   int skewport_extrapolation_limit_in_content_pixels;
   size_t max_unused_resource_memory_percentage;
   size_t max_memory_for_prepaint_percentage;
   bool strict_layer_property_change_checking;
   bool use_one_copy;
   bool use_zero_copy;
   bool use_persistent_map_for_gpu_memory_buffers;
   bool enable_elastic_overscroll;
-  unsigned use_image_texture_target;
+  // an array of image texture targets for each GpuMemoryBuffer format

[reveman, 2015/07/28 08:58:26]

nit: s/an array../An array/ and s/format/format./

+  std::vector<unsigned> use_image_texture_targets;

[piman, 2015/07/28 16:33:22]

Why not an array? The size is known statically.

[jchen10, 2015/07/29 04:33:47]

I had wished to use an array from the start. But gave up it in order to keep the
patch more concise, since vector is handier than raw array. The initial thoughts
at that moment were:
1. The initializer function vector(count, value) could be used frequently in the
patch, so the code to re-invent it for array could be saved.
2. Vector can be passed as an parameter either by value or reference. Whereas
you have to manually copy all elements for an array in case of pass-by-value.
3. No need to include "ui/gfx/gpu_memory_buffer.h" everywhere merely for the
array size defined in it.
4. Performance penalty should be insignificant because there are a very small
number of elements.

   bool ignore_root_layer_flings;
   size_t scheduled_raster_task_limit;
   bool use_occlusion_for_tile_prioritization;
   bool record_full_layer;
   bool use_display_lists;
   bool verify_property_trees;
   bool gather_pixel_refs;
   bool use_compositor_animation_timelines;
   bool invert_viewport_scroll_order;
   bool wait_for_beginframe_interval;
 
   LayerTreeDebugState initial_debug_state;
 
   SchedulerSettings ToSchedulerSettings() const;
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_SETTINGS_H_