gpu: Assign unique ids to anonymous io surfaces.

crrev.com/804597 accidentally set gmb id for anonymous surfaces to 0 to
use it as a hint for whether to clear surfaces. This causes a memory
regression similar to the one before unique ids were introduced.

Instead, client_id, which is 0 for anonymous images and non-zero
otherwise, can be used for the same purpose.

R=ccameron
BUG=793445

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I76b2fa6cf498b0f2727bef7983ebc063cfb5e9d0
Reviewed-on: https://chromium-review.googlesource.com/820618Reviewed-by: ccameron <ccameron@chromium.org>
Reviewed-by: David Reveman <reveman@chromium.org>
Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523580}

gpu/ipc/service/gpu_memory_buffer_factory_io_surface.cc

@@ -29,7 +29,7 @@ GpuMemoryBufferFactoryIOSurface::CreateGpuMemoryBuffer(
     int client_id,
     SurfaceHandle surface_handle) {
   // Don't clear anonymous io surfaces.
-  bool should_clear = id.is_valid();
+  bool should_clear = (client_id != 0);
   base::ScopedCFTypeRef<IOSurfaceRef> io_surface(
       gfx::CreateIOSurface(size, format, should_clear));
   if (!io_surface)
@@ -99,9 +99,9 @@ GpuMemoryBufferFactoryIOSurface::CreateAnonymousImage(const gfx::Size& size,
                                                       bool* is_cleared) {
   // Note that the child id doesn't matter since the texture will never be
   // directly exposed to other processes, only via a mailbox.
-  gfx::GpuMemoryBufferHandle handle =
-      CreateGpuMemoryBuffer(gfx::GpuMemoryBufferId(), size, format, usage,
-                            0 /* client_id */, gpu::kNullSurfaceHandle);
+  gfx::GpuMemoryBufferHandle handle = CreateGpuMemoryBuffer(
+      gfx::GpuMemoryBufferId(next_anonymous_image_id_++), size, format, usage,
+      0 /* client_id */, gpu::kNullSurfaceHandle);
 
   base::ScopedCFTypeRef<IOSurfaceRef> io_surface;
   io_surface.reset(IOSurfaceLookupFromMachPort(handle.mach_port.get()));

gpu/ipc/service/gpu_memory_buffer_factory_io_surface.h

@@ -71,6 +71,9 @@ class GPU_EXPORT GpuMemoryBufferFactoryIOSurface
   IOSurfaceMap io_surfaces_;
   base::Lock io_surfaces_lock_;
 
+  // Assign unique ids to anonymous images to differentiate in memory dumps.
+  int next_anonymous_image_id_ = 1;
+
   DISALLOW_COPY_AND_ASSIGN(GpuMemoryBufferFactoryIOSurface);
 };