Do not give GPU memory to backgrounded compositors.

cc/output/gl_renderer_unittest.cc

 // Copyright 2012 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 "cc/output/gl_renderer.h"
 
 #include <set>
 
 #include "cc/base/math_util.h"
 #include "cc/output/compositor_frame_metadata.h"
@@ skipping 367 matching lines @@
   LayerTreeSettings settings_;
   FakeOutputSurfaceClient output_surface_client_;
   scoped_ptr<FakeOutputSurface> output_surface_;
   FakeRendererClient renderer_client_;
   scoped_ptr<ResourceProvider> resource_provider_;
   scoped_ptr<FakeRendererGL> renderer_;
 };
 
 namespace {
 
-// Test GLRenderer discardBackbuffer functionality:
-// Suggest recreating framebuffer when one already exists.
-// Expected: it does nothing.
-TEST_F(GLRendererTest, SuggestBackbufferYesWhenItAlreadyExistsShouldDoNothing) {
-  renderer_->SetDiscardBackBufferWhenNotVisible(false);
-  EXPECT_EQ(0, renderer_client_.set_full_root_layer_damage_count());
-  EXPECT_FALSE(renderer_->IsBackbufferDiscarded());
-
-  SwapBuffers();
-  EXPECT_EQ(1, context3d_->frame_count());
-}
-
 // Test GLRenderer DiscardBackbuffer functionality:
 // Suggest discarding framebuffer when one exists and the renderer is not
 // visible.
 // Expected: it is discarded and damage tracker is reset.
 TEST_F(
     GLRendererTest,
     SuggestBackbufferNoShouldDiscardBackbufferAndDamageRootLayerIfNotVisible) {
   renderer_->SetVisible(false);
-  renderer_->SetDiscardBackBufferWhenNotVisible(true);
   EXPECT_EQ(1, renderer_client_.set_full_root_layer_damage_count());
   EXPECT_TRUE(renderer_->IsBackbufferDiscarded());
 }
 
 // Test GLRenderer DiscardBackbuffer functionality:
 // Suggest discarding framebuffer when one exists and the renderer is visible.
 // Expected: the allocation is ignored.
 TEST_F(GLRendererTest, SuggestBackbufferNoDoNothingWhenVisible) {
   renderer_->SetVisible(true);
-  renderer_->SetDiscardBackBufferWhenNotVisible(true);
   EXPECT_EQ(0, renderer_client_.set_full_root_layer_damage_count());
   EXPECT_FALSE(renderer_->IsBackbufferDiscarded());
 }
 
 // Test GLRenderer DiscardBackbuffer functionality:
 // Suggest discarding framebuffer when one does not exist.
 // Expected: it does nothing.
 TEST_F(GLRendererTest, SuggestBackbufferNoWhenItDoesntExistShouldDoNothing) {
   renderer_->SetVisible(false);
-  renderer_->SetDiscardBackBufferWhenNotVisible(true);
   EXPECT_EQ(1, renderer_client_.set_full_root_layer_damage_count());
   EXPECT_TRUE(renderer_->IsBackbufferDiscarded());
 
-  renderer_->SetDiscardBackBufferWhenNotVisible(true);
   EXPECT_EQ(1, renderer_client_.set_full_root_layer_damage_count());
   EXPECT_TRUE(renderer_->IsBackbufferDiscarded());
 }
 
 // Test GLRenderer DiscardBackbuffer functionality:
 // Begin drawing a frame while a framebuffer is discarded.
 // Expected: will recreate framebuffer.
 TEST_F(GLRendererTest, DiscardedBackbufferIsRecreatedForScopeDuration) {
   renderer_->SetVisible(false);
-  renderer_->SetDiscardBackBufferWhenNotVisible(true);
   EXPECT_TRUE(renderer_->IsBackbufferDiscarded());
   EXPECT_EQ(1, renderer_client_.set_full_root_layer_damage_count());
 
   renderer_->SetVisible(true);
   renderer_->DrawFrame(
       renderer_client_.render_passes_in_draw_order(), NULL, 1.f, true, false);
   EXPECT_FALSE(renderer_->IsBackbufferDiscarded());
 
   SwapBuffers();
   EXPECT_EQ(1, context3d_->frame_count());
 }
 
 TEST_F(GLRendererTest, FramebufferDiscardedAfterReadbackWhenNotVisible) {
   renderer_->SetVisible(false);
-  renderer_->SetDiscardBackBufferWhenNotVisible(true);
   EXPECT_TRUE(renderer_->IsBackbufferDiscarded());
   EXPECT_EQ(1, renderer_client_.set_full_root_layer_damage_count());
 
   char pixels[4];
   renderer_->DrawFrame(
       renderer_client_.render_passes_in_draw_order(), NULL, 1.f, true, false);
   EXPECT_FALSE(renderer_->IsBackbufferDiscarded());
 
   renderer_->GetFramebufferPixels(pixels, gfx::Rect(0, 0, 1, 1));
   EXPECT_TRUE(renderer_->IsBackbufferDiscarded());
@@ skipping 1395 matching lines @@
   base::MessageLoop::current()->Run();
 
   // The sync point should have happened.
   EXPECT_EQ(1, sync_point_callback_count);
   EXPECT_EQ(1, other_callback_count);
 }
 #endif  // OS_ANDROID
 
 }  // namespace
 }  // namespace cc