Properly check handle type in GpuMemoryBufferFactory*

Calling code (CommandBufferStub via GpuChannel) doesn't check that the
GMB handle type corresponds to the correct platform-specific handle
(indeed it doesn't have a way to). So check in the
GpuMemoryBufferFactory* classes and fail if the handle type is invalid.

Bug: 870116
Change-Id: I78b574439350bee3dccda569e53eae7f74c7d0a7
Reviewed-on: https://chromium-review.googlesource.com/c/1316168Reviewed-by: Victor Miura <vmiura@chromium.org>
Commit-Queue: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605127}

gpu/ipc/service/gpu_memory_buffer_factory_android_hardware_buffer.cc

@@ -66,9 +66,8 @@ GpuMemoryBufferFactoryAndroidHardwareBuffer::CreateImageForGpuMemoryBuffer(
     gfx::BufferFormat format,
     int client_id,
     SurfaceHandle surface_handle) {
-  // We should only end up in this code path if the memory buffer has a valid
-  // AHardwareBuffer.
-  DCHECK_EQ(handle.type, gfx::ANDROID_HARDWARE_BUFFER);
+  if (handle.type != gfx::ANDROID_HARDWARE_BUFFER)
+    return nullptr;
 
   base::android::ScopedHardwareBufferHandle& buffer =
       handle.android_hardware_buffer;

gpu/ipc/service/gpu_memory_buffer_factory_io_surface.cc

@@ -111,9 +111,11 @@ GpuMemoryBufferFactoryIOSurface::CreateImageForGpuMemoryBuffer(
     gfx::BufferFormat format,
     int client_id,
     SurfaceHandle surface_handle) {
+  if (handle.type != gfx::IO_SURFACE_BUFFER)
+    return nullptr;
+
   base::AutoLock lock(io_surfaces_lock_);
 
-  DCHECK_EQ(handle.type, gfx::IO_SURFACE_BUFFER);
   IOSurfaceMapKey key(handle.id, client_id);
   IOSurfaceMap::iterator it = io_surfaces_.find(key);
   if (it == io_surfaces_.end()) {

gpu/ipc/service/gpu_memory_buffer_factory_native_pixmap.cc

@@ -85,7 +85,8 @@ GpuMemoryBufferFactoryNativePixmap::CreateImageForGpuMemoryBuffer(
     gfx::BufferFormat format,
     int client_id,
     SurfaceHandle surface_handle) {
-  DCHECK_EQ(handle.type, gfx::NATIVE_PIXMAP);
+  if (handle.type != gfx::NATIVE_PIXMAP)
+    return nullptr;
 
   scoped_refptr<gfx::NativePixmap> pixmap;