Don't create manager objects in ContextGroup when using the passthrough decoder

These objects are not used when the passthrough command decoder is in
use.  This saves several GPU memory allocations in TextureManager for
default and black textures.

Saves ~2 MB per context.

This is a reland of https://chromium-review.googlesource.com/c/chromium/src/+/2028291

TBR=sandersd@chromium.org

BUG=1046613
BUG=1030835

Change-Id: Iae138dd860023d3b16e958fed290ad78188b31bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2072358
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Auto-Submit: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#745174}

gpu/command_buffer/service/context_group.cc

@@ -263,13 +263,17 @@ gpu::ContextResult ContextGroup::Initialize(
                 &uniform_buffer_offset_alignment_);
   }
 
-  buffer_manager_ = std::make_unique<BufferManager>(memory_tracker_.get(),
-                                                    feature_info_.get());
-  renderbuffer_manager_ = std::make_unique<RenderbufferManager>(
-      memory_tracker_.get(), max_renderbuffer_size, max_samples,
-      feature_info_.get());
-  shader_manager_ = std::make_unique<ShaderManager>(progress_reporter_);
-  sampler_manager_ = std::make_unique<SamplerManager>(feature_info_.get());
+  // Managers are not used by the passthrough command decoder. Save memory by
+  // not allocating them.
+  if (!use_passthrough_cmd_decoder_) {
+    buffer_manager_ = std::make_unique<BufferManager>(memory_tracker_.get(),
+                                                      feature_info_.get());
+    renderbuffer_manager_ = std::make_unique<RenderbufferManager>(
+        memory_tracker_.get(), max_renderbuffer_size, max_samples,
+        feature_info_.get());
+    shader_manager_ = std::make_unique<ShaderManager>(progress_reporter_);
+    sampler_manager_ = std::make_unique<SamplerManager>(feature_info_.get());
+  }
 
   // Lookup GL things we need to know.
   const GLint kGLES2RequiredMinimumVertexAttribs = 8u;
@@ -389,11 +393,15 @@ gpu::ContextResult ContextGroup::Initialize(
                  feature_info_->workarounds().max_3d_array_texture_size);
   }
 
-  texture_manager_.reset(new TextureManager(
-      memory_tracker_.get(), feature_info_.get(), max_texture_size,
-      max_cube_map_texture_size, max_rectangle_texture_size,
-      max_3d_texture_size, max_array_texture_layers, bind_generates_resource_,
-      progress_reporter_, discardable_manager_));
+  // Managers are not used by the passthrough command decoder. Save memory by
+  // not allocating them.
+  if (!use_passthrough_cmd_decoder_) {
+    texture_manager_.reset(new TextureManager(
+        memory_tracker_.get(), feature_info_.get(), max_texture_size,
+        max_cube_map_texture_size, max_rectangle_texture_size,
+        max_3d_texture_size, max_array_texture_layers, bind_generates_resource_,
+        progress_reporter_, discardable_manager_));
+  }
 
   const GLint kMinTextureImageUnits = 8;
   const GLint kMinVertexTextureImageUnits = 0;
@@ -523,14 +531,18 @@ gpu::ContextResult ContextGroup::Initialize(
     }
   }
 
-  path_manager_ = std::make_unique<PathManager>();
+  // Managers are not used by the passthrough command decoder. Save memory by
+  // not allocating them.
+  if (!use_passthrough_cmd_decoder_) {
+    path_manager_ = std::make_unique<PathManager>();
 
-  program_manager_ = std::make_unique<ProgramManager>(
-      program_cache_, max_varying_vectors_, max_draw_buffers_,
-      max_dual_source_draw_buffers_, max_vertex_attribs_, gpu_preferences_,
-      feature_info_.get(), progress_reporter_);
+    program_manager_ = std::make_unique<ProgramManager>(
+        program_cache_, max_varying_vectors_, max_draw_buffers_,
+        max_dual_source_draw_buffers_, max_vertex_attribs_, gpu_preferences_,
+        feature_info_.get(), progress_reporter_);
 
-  texture_manager_->Initialize();
+    texture_manager_->Initialize();
+  }
 
   decoders_.push_back(decoder->AsWeakPtr());
   return gpu::ContextResult::kSuccess;

media/gpu/android/direct_shared_image_video_provider.cc

@@ -199,9 +199,6 @@ bool GpuSharedImageVideoFactory::CreateImageInternal(
   gpu::gles2::ContextGroup* group = stub_->decoder_context()->GetContextGroup();
   if (!group)
     return false;
-  gpu::gles2::TextureManager* texture_manager = group->texture_manager();
-  if (!texture_manager)
-    return false;
 
   const auto& size = spec.size;
 

media/gpu/command_buffer_helper.cc

@@ -15,7 +15,6 @@
 #include "gpu/command_buffer/service/decoder_context.h"
 #include "gpu/command_buffer/service/scheduler.h"
 #include "gpu/command_buffer/service/sync_point_manager.h"
-#include "gpu/command_buffer/service/texture_manager.h"
 #include "gpu/ipc/service/command_buffer_stub.h"
 #include "gpu/ipc/service/gpu_channel.h"
 #include "media/gpu/gles2_decoder_helper.h"

media/gpu/gles2_decoder_helper.cc

@@ -14,7 +14,6 @@
 #include "gpu/command_buffer/service/context_group.h"
 #include "gpu/command_buffer/service/decoder_context.h"
 #include "gpu/command_buffer/service/mailbox_manager.h"
-#include "gpu/command_buffer/service/texture_manager.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/scoped_binders.h"
 
@@ -28,10 +27,7 @@ class GLES2DecoderHelperImpl : public GLES2DecoderHelper {
       : decoder_(decoder) {
     DCHECK(decoder_);
     gpu::gles2::ContextGroup* group = decoder_->GetContextGroup();
-    texture_manager_ = group->texture_manager();
     mailbox_manager_ = group->mailbox_manager();
-    // TODO(sandersd): Support GLES2DecoderPassthroughImpl.
-    DCHECK(texture_manager_);
     DCHECK(mailbox_manager_);
   }
 
@@ -97,7 +93,6 @@ class GLES2DecoderHelperImpl : public GLES2DecoderHelper {
 
  private:
   gpu::DecoderContext* decoder_;
-  gpu::gles2::TextureManager* texture_manager_;
   gpu::MailboxManager* mailbox_manager_;
   THREAD_CHECKER(thread_checker_);