Add R_8 GPU memory buffers format.

content/common/gpu/client/gpu_memory_buffer_impl.cc

 // Copyright 2013 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 "content/common/gpu/client/gpu_memory_buffer_impl.h"
 
 #include "base/logging.h"
 #include "base/numerics/safe_math.h"
 #include "content/common/gpu/client/gpu_memory_buffer_impl_shared_memory.h"
 #include "ui/gl/gl_bindings.h"
@@ skipping 67 matching lines @@
 
 // static
 size_t GpuMemoryBufferImpl::NumberOfPlanesForGpuMemoryBufferFormat(
     Format format) {
   switch (format) {
     case ATC:
     case ATCIA:
     case DXT1:
     case DXT5:
     case ETC1:
+    case R_8:
     case RGBA_8888:
     case RGBX_8888:
     case BGRA_8888:
       return 1;
     case YUV_420:
       return 3;
   }
   NOTREACHED();
   return 0;
 }
 
 // static
 bool GpuMemoryBufferImpl::StrideInBytes(size_t width,
                                         Format format,
                                         int plane,
                                         size_t* stride_in_bytes) {
+  base::CheckedNumeric<size_t> checked_stride = width;
   switch (format) {
     case ATCIA:
     case DXT5:
       DCHECK_EQ(plane, 0);
       *stride_in_bytes = width;
       return true;
     case ATC:
     case DXT1:
     case ETC1:
       DCHECK_EQ(plane, 0);
-      DCHECK_EQ(width % 2, 0U);
+      DCHECK_EQ(width % 2, 0u);
       *stride_in_bytes = width / 2;
       return true;
+    case R_8:
+      checked_stride += 3;
+      if (!checked_stride.IsValid())
+        return false;
+      *stride_in_bytes = checked_stride.ValueOrDie() & ~0x3;
+      return true;
+    case RGBX_8888:
     case RGBA_8888:
-    case RGBX_8888:
-    case BGRA_8888: {
-      base::CheckedNumeric<size_t> s = width;
-      DCHECK_EQ(plane, 0);
-      s *= 4;
-      if (!s.IsValid())
+    case BGRA_8888:
+      checked_stride *= 4;
+      if (!checked_stride.IsValid())
         return false;
-      *stride_in_bytes = s.ValueOrDie();
+      *stride_in_bytes = checked_stride.ValueOrDie();
       return true;
-    }
-    case YUV_420: {
+    case YUV_420:
       DCHECK_EQ(width % 2, 0u);
       *stride_in_bytes = width / SubsamplingFactor(format, plane);
       return true;
-    }
   }
+
   NOTREACHED();
   return false;
 }
 
 // static
 size_t GpuMemoryBufferImpl::SubsamplingFactor(
     Format format,
     int plane) {
   switch (format) {
     case ATC:
     case ATCIA:
     case DXT1:
     case DXT5:
     case ETC1:
+    case R_8:
     case RGBA_8888:
     case RGBX_8888:
     case BGRA_8888:
       return 1;
     case YUV_420: {
       static size_t factor[] = {1, 2, 2};
       DCHECK_LT(static_cast<size_t>(plane), arraysize(factor));
       return factor[plane];
     }
   }
   NOTREACHED();
   return 0;
 }
 
 gfx::GpuMemoryBuffer::Format GpuMemoryBufferImpl::GetFormat() const {
   return format_;
 }
 
 bool GpuMemoryBufferImpl::IsMapped() const {
   return mapped_;
 }
 
 ClientBuffer GpuMemoryBufferImpl::AsClientBuffer() {
   return reinterpret_cast<ClientBuffer>(this);
 }
 
 }  // namespace content