Allow creating GLImage-backed textures with glTexStorage2D.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 0bb39bb087bb191b6f55eaf303e70ae2af94b9af..7ed4a061194784d56aa808683971babb741b9112 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -2849,7 +2849,7 @@ bool BackTexture::AllocateNativeGpuMemoryBuffer(const gfx::Size& size,
               gfx::BufferFormat::RGBX_8888
 #endif
               : gfx::BufferFormat::RGBA_8888,
-          format);
+          gfx::BufferUsage::SCANOUT, format);
   if (!image || !image->BindTexImage(Target()))
     return false;
 
@@ -3887,6 +3887,8 @@ Capabilities GLES2DecoderImpl::GetCapabilities() {
       !surface_->IsOffscreen()) {
     caps.disable_non_empty_post_sub_buffers = true;
   }
+  caps.texture_buffer_chromium =
+      feature_info_->feature_flags().chromium_texture_buffer;
 
   return caps;
 }
@@ -10990,6 +10992,13 @@ void GLES2DecoderImpl::GetTexParameterImpl(
         iparams[0] = texture->swizzle_a();
       }
       return;
+    case GL_TEXTURE_BUFFER_USAGE_CHROMIUM:
+      if (fparams) {
+        fparams[0] = static_cast<GLfloat>(texture->buffer_usage());
+      } else {
+        iparams[0] = texture->buffer_usage();
+      }
+      return;
     default:
       break;
   }
@@ -17569,6 +17578,62 @@ void GLES2DecoderImpl::TexStorageImpl(GLenum target,
     return;
   }
 
+  if (texture->buffer_usage() != GL_NONE) {
+    ScopedGLErrorSuppressor suppressor("GLES2CmdDecoder::TexStorageImpl",
+                                       state_.GetErrorState());
+    gfx::Size size(width, height);
+    gfx::BufferFormat buffer_format;
+    GLint real_internal_format;
+    switch (internal_format) {
+      case GL_RGBA8_OES:
+        buffer_format = gfx::BufferFormat::RGBA_8888;
+        real_internal_format = GL_RGBA;
+        break;
+      case GL_BGRA8_EXT:
+        buffer_format = gfx::BufferFormat::BGRA_8888;
+        real_internal_format = GL_BGRA_EXT;
+        break;
+      case GL_RGBA16F_EXT:
+        buffer_format = gfx::BufferFormat::RGBA_F16;
+        real_internal_format = GL_RGBA;
+        break;
+      default:
+        LOCAL_SET_GL_ERROR(GL_INVALID_ENUM, function_name,
+                           "Invalid buffer format");
+        return;
+    }
+
+    if (levels != 1) {
+      LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name,
+                         "Levels != 1 for buffer");
+      return;
+    }
+    if (depth > 1) {
+      LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name,
+                         "depth > 1 for buffer");
+      return;
+    }
+    DCHECK_EQ(GL_TEXTURE_BUFFER_SCANOUT_CHROMIUM, texture->buffer_usage());
+
+    gfx::BufferUsage buffer_usage = gfx::BufferUsage::SCANOUT;
+    scoped_refptr<gl::GLImage> image =
+        GetContextGroup()->image_factory()->CreateAnonymousImage(
+            gfx::Size(width, height), buffer_format, buffer_usage,
+            real_internal_format);
+    if (!image || !image->BindTexImage(target)) {
+      LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, function_name,
+                         "Cannot create GL Image");
+      return;
+    }
+
+    texture_manager()->SetLevelInfo(
+        texture_ref, target, 0, image->GetInternalFormat(), width, height, 1, 0,
+        image->GetInternalFormat(), GL_UNSIGNED_BYTE, gfx::Rect(size));
+    texture_manager()->SetLevelImage(texture_ref, target, 0, image.get(),
+                                     Texture::BOUND);
+    return;
+  }
+
   GLenum format = TextureManager::ExtractFormatFromStorageFormat(
       internal_format);
   GLenum type = TextureManager::ExtractTypeFromStorageFormat(internal_format);