Update GPU memory buffers to use StrideInBytes internally.

content/common/gpu/gpu_memory_buffer_factory_io_surface.cc

Index: content/common/gpu/gpu_memory_buffer_factory_io_surface.cc
diff --git a/content/common/gpu/gpu_memory_buffer_factory_io_surface.cc b/content/common/gpu/gpu_memory_buffer_factory_io_surface.cc
index ba00ea2553a2600002baee58b12b5ee9cdb9a4c0..5b0174f4064e03e7a26ac9cbe4f48d71d5889991 100644
--- a/content/common/gpu/gpu_memory_buffer_factory_io_surface.cc
+++ b/content/common/gpu/gpu_memory_buffer_factory_io_surface.cc
@@ -94,6 +94,9 @@ GpuMemoryBufferFactoryIOSurface::CreateGpuMemoryBuffer(
     gfx::GpuMemoryBuffer::Usage usage,
     int client_id,
     gfx::PluginWindowHandle surface_handle) {
+  size_t width_in_bytes =
+      GpuMemoryBufferImpl::StrideInBytes(size.width(), format);
+  DCHECK_EQ(width_in_bytes % size.width(), 0u);
   base::ScopedCFTypeRef<CFMutableDictionaryRef> properties;
   properties.reset(CFDictionaryCreateMutable(kCFAllocatorDefault,
                                              0,
@@ -101,7 +104,8 @@ GpuMemoryBufferFactoryIOSurface::CreateGpuMemoryBuffer(
                                              &kCFTypeDictionaryValueCallBacks));
   AddIntegerValue(properties, kIOSurfaceWidth, size.width());
   AddIntegerValue(properties, kIOSurfaceHeight, size.height());
-  AddIntegerValue(properties, kIOSurfaceBytesPerElement, BytesPerPixel(format));
+  AddIntegerValue(properties, kIOSurfaceBytesPerElement,
+                  width_in_bytes / size.width());

[reveman, 2014/12/18 18:49:57]

nit: Please keep using BytesPerPixel here instead. Deriving bpp from the stride
feels backwards and fragile. I think it's fine that some implementations don't
use StrideInBytes. Maybe just DCHECK_EQ(BytesPerPixel(format) * width,
StrideInBytes(width, format)) if we're using StrideInBytes in
GpuMemoryBufferImplIOSurface.

[christiank, 2015/01/12 10:35:22]

Alright, I missed that this file actually had its own BytesPerPixel function.

   AddIntegerValue(properties, kIOSurfacePixelFormat, PixelFormat(format));
   // TODO(reveman): Remove this when using a mach_port_t to transfer
   // IOSurface to browser and renderer process. crbug.com/323304