Re-land: content: Enable native GpuMemoryBuffers by default on MacOSX.

content/browser/gpu/browser_gpu_memory_buffer_manager.cc

Index: content/browser/gpu/browser_gpu_memory_buffer_manager.cc
diff --git a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
index 23d2b50efd5179d06676a057e067b2238793b33a..acf1ccf498611068a69561e858e9560741eb9f31 100644
--- a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
+++ b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
@@ -19,6 +19,7 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/content_switches.h"
 #include "gpu/GLES2/gl2extchromium.h"
+#include "ui/gl/gl_switches.h"
 
 #if defined(OS_MACOSX)
 #include "content/common/gpu/gpu_memory_buffer_factory_io_surface.h"
@@ -87,8 +88,23 @@ gfx::GpuMemoryBufferType GetGpuMemoryBufferFactoryType() {
 std::vector<GpuMemoryBufferFactory::Configuration>
 GetSupportedGpuMemoryBufferConfigurations(gfx::GpuMemoryBufferType type) {
   std::vector<GpuMemoryBufferFactory::Configuration> configurations;
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kEnableNativeGpuMemoryBuffers)) {
+#if defined(OS_MACOSX)
+  bool enable_native_gpu_memory_buffers =
+      !base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableNativeGpuMemoryBuffers);
+#else
+  bool enable_native_gpu_memory_buffers =
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableNativeGpuMemoryBuffers);
+#endif
+
+  // Disable native buffers when using Mesa.
+  if (base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+          switches::kUseGL) == gfx::kGLImplementationOSMesaName) {
+    enable_native_gpu_memory_buffers = false;
+  }
+
+  if (enable_native_gpu_memory_buffers) {
     const GpuMemoryBufferFactory::Configuration kNativeConfigurations[] = {
         {gfx::GpuMemoryBuffer::R_8, gfx::GpuMemoryBuffer::MAP},
         {gfx::GpuMemoryBuffer::R_8, gfx::GpuMemoryBuffer::PERSISTENT_MAP},