Refactor OS_LINUX preprocessor directive for LaCrOS effort.

Currently, ChromeOS defines the OS_LINUX directive as well as
OS_CHROMEOS.  We're working to separate these two, so we're
making the fact that OS_LINUX == OS_LINUX || OS_CHROMEOS
explicit.

This is changes for /gpu/ipc/common/gpu_memory_buffer_support.cc

This CL was uploaded by git cl split.

R=dcastagna@chromium.org

Bug: 1110266
Change-Id: I705cdbdfdafafc7a8aeb77a5c9f6ea0a4e171ba5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2371297Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Sean McAllister <smcallis@google.com>
Cr-Commit-Position: refs/heads/master@{#801976}

gpu/ipc/common/gpu_memory_buffer_support.cc

@@ -16,7 +16,7 @@
 #include "gpu/ipc/common/gpu_memory_buffer_impl_io_surface.h"
 #endif
 
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
 #include "ui/gfx/client_native_pixmap_factory.h"
 #include "ui/gfx/linux/client_native_pixmap_factory_dmabuf.h"
 #endif
@@ -26,7 +26,7 @@
 #include "ui/ozone/public/ozone_platform.h"
 #endif
 
-#if defined(USE_OZONE) || defined(OS_LINUX)
+#if defined(USE_OZONE) || defined(OS_LINUX) || defined(OS_CHROMEOS)
 #include "gpu/ipc/common/gpu_memory_buffer_impl_native_pixmap.h"
 #endif
 
@@ -52,7 +52,7 @@ GpuMemoryBufferSupport::GpuMemoryBufferSupport() {
     return;
   }
 #endif
-#if defined(OS_LINUX)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS)
   client_native_pixmap_factory_.reset(
       gfx::CreateClientNativePixmapFactoryDmabuf());
 #endif
@@ -66,7 +66,7 @@ GpuMemoryBufferSupport::GetNativeGpuMemoryBufferType() {
   return gfx::IO_SURFACE_BUFFER;
 #elif defined(OS_ANDROID)
   return gfx::ANDROID_HARDWARE_BUFFER;
-#elif defined(OS_LINUX) || defined(USE_OZONE)
+#elif defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(USE_OZONE)
   return gfx::NATIVE_PIXMAP;
 #elif defined(OS_WIN)
   return gfx::DXGI_SHARED_HANDLE;
@@ -194,7 +194,7 @@ GpuMemoryBufferSupport::CreateGpuMemoryBufferImplFromHandle(
       return GpuMemoryBufferImplIOSurface::CreateFromHandle(
           std::move(handle), size, format, usage, std::move(callback));
 #endif
-#if defined(OS_LINUX) || defined(USE_OZONE)
+#if defined(OS_LINUX) || defined(OS_CHROMEOS) || defined(USE_OZONE)
     case gfx::NATIVE_PIXMAP:
       return GpuMemoryBufferImplNativePixmap::CreateFromHandle(
           client_native_pixmap_factory(), std::move(handle), size, format,