color: Ensure solid color IOSurface layers are sRGB

ui/gfx/mac/io_surface.cc

 // Copyright 2015 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.
 
 #include "ui/gfx/mac/io_surface.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
+#include "base/command_line.h"
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/mach_logging.h"
 #include "base/macros.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/gfx/buffer_format_util.h"
+#include "ui/gfx/switches.h"
 
 namespace gfx {
 
 namespace {
 
 void AddIntegerValue(CFMutableDictionaryRef dictionary,
                      const CFStringRef key,
                      int32_t value) {
   base::ScopedCFTypeRef<CFNumberRef> number(
       CFNumberCreate(NULL, kCFNumberSInt32Type, &value));
@@ skipping 153 matching lines @@
 
   if (should_clear) {
     // Zero-initialize the IOSurface. Calling IOSurfaceLock/IOSurfaceUnlock
     // appears to be sufficient. https://crbug.com/584760#c17
     IOReturn r = IOSurfaceLock(surface, 0, nullptr);
     DCHECK_EQ(kIOReturnSuccess, r);
     r = IOSurfaceUnlock(surface, 0, nullptr);
     DCHECK_EQ(kIOReturnSuccess, r);
   }
 
-  bool force_system_color_space = false;
+  bool force_color_space = false;
 
   // Displaying an IOSurface that does not have a color space using an
-  // AVSampleBufferDisplayLayer can result in a black screen. Specify the
-  // main display's color profile by default, which will result in no color
-  // correction being done for the main monitor (which is the behavior of not
-  // specifying a color space).
+  // AVSampleBufferDisplayLayer can result in a black screen. Ensure that
+  // a color space always be specified.

[Avi (use Gerrit), 2017/05/09 14:53:22]

... always is specified.

? I'm in an argument with myself over whether the current phrasing is officially
grammatical and I'm just not sure.

[ccameron, 2017/05/09 16:18:25]

This was intended to be the subjunctive mood ... but I'm not 100% sure if the
subjunctive is appropriate for describing what happens in branches of
if-statements.

   // https://crbug.com/608879
   if (format == gfx::BufferFormat::YUV_420_BIPLANAR)
-    force_system_color_space = true;
+    force_color_space = true;
 
   // On Sierra, all IOSurfaces are color corrected as though they are in sRGB
   // color space by default. Prior to Sierra, IOSurfaces were not color
   // corrected (they were treated as though they were in the display color
   // space). Override this by defaulting IOSurfaces to be in the main display
   // color space.
   // https://crbug.com/654488
   if (base::mac::IsAtLeastOS10_12())
-    force_system_color_space = true;
+    force_color_space = true;
 
-  if (force_system_color_space) {
-    CGColorSpaceRef color_space = base::mac::GetSystemColorSpace();
+  // Ensure that all IOSurfaces start as sRGB when color correct rendering
+  // is enabled.
+  static bool color_correct_rendering_enabled =
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableColorCorrectRendering);
+  if (color_correct_rendering_enabled)
+    force_color_space = true;
+
+  if (force_color_space) {
+    CGColorSpaceRef color_space = color_correct_rendering_enabled
+                                      ? base::mac::GetSRGBColorSpace()
+                                      : base::mac::GetSystemColorSpace();
     base::ScopedCFTypeRef<CFDataRef> color_space_icc(
         CGColorSpaceCopyICCProfile(color_space));
     // Note that nullptr is an acceptable input to IOSurfaceSetValue.
     IOSurfaceSetValue(surface, CFSTR("IOSurfaceColorSpace"), color_space_icc);
   }
 
   UMA_HISTOGRAM_TIMES("GPU.IOSurface.CreateTime",
                       base::TimeTicks::Now() - start_time);
   return surface;
 }
 
 }  // namespace gfx