Add CONTEXT_TYPE_OPENGLES2_PEPPER

Adds a new context type for Pepper GL contexts. This allows us to
fine tune driver bug workarounds for pepper vs. non-pepper contexts.

Currently used to disable the Intel MSAA blacklist on pepper contexts,
as it should be up to the app whether to use MSAA.

BUG=527565
CQ_INCLUDE_TRYBOTS=tryserver.chromium.win:win_optional_gpu_tests_rel;tryserver.chromium.mac:mac_optional_gpu_tests_rel

Review URL: https://codereview.chromium.org/1781093002

Cr-Commit-Position: refs/heads/master@{#382097}

4 files changed, 53 insertions, 2 deletions

diff --git a/cc/output/delegating_renderer.cc b/cc/output/delegating_renderer.cc
index 365ee85..1bd7d0a 100644
--- a/cc/output/delegating_renderer.cc
+++ b/cc/output/delegating_renderer.cc
@@ -56,7 +56,13 @@ DelegatingRenderer::DelegatingRenderer(RendererClient* client,
     capabilities_.using_image = caps.gpu.image;
 
     capabilities_.allow_rasterize_on_demand = false;
-    capabilities_.max_msaa_samples = caps.gpu.max_samples;
+
+    // If MSAA is slow, we want this renderer to behave as though MSAA is not
+    // available. Set samples to 0 to achieve this.
+    if (caps.gpu.msaa_is_slow)
+      capabilities_.max_msaa_samples = 0;
+    else
+      capabilities_.max_msaa_samples = caps.gpu.max_samples;
   }
 }
 
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index 77ff5ca..e264257 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -373,7 +373,13 @@ GLRenderer::GLRenderer(RendererClient* client,
       context_caps.gpu.discard_framebuffer;
 
   capabilities_.allow_rasterize_on_demand = true;
-  capabilities_.max_msaa_samples = context_caps.gpu.max_samples;
+
+  // If MSAA is slow, we want this renderer to behave as though MSAA is not
+  // available. Set samples to 0 to achieve this.
+  if (context_caps.gpu.msaa_is_slow)
+    capabilities_.max_msaa_samples = 0;
+  else
+    capabilities_.max_msaa_samples = context_caps.gpu.max_samples;
 
   use_sync_query_ = context_caps.gpu.sync_query;
   use_blend_equation_advanced_ = context_caps.gpu.blend_equation_advanced;
diff --git a/cc/test/test_web_graphics_context_3d.h b/cc/test/test_web_graphics_context_3d.h
index f497ac4..a913eda 100644
--- a/cc/test/test_web_graphics_context_3d.h
+++ b/cc/test/test_web_graphics_context_3d.h
@@ -350,6 +350,9 @@ class TestWebGraphicsContext3D {
   void set_support_texture_half_float_linear(bool support) {
     test_capabilities_.gpu.texture_half_float_linear = support;
   }
+  void set_msaa_is_slow(bool msaa_is_slow) {
+    test_capabilities_.gpu.msaa_is_slow = msaa_is_slow;
+  }
 
   // When this context is lost, all contexts in its share group are also lost.
   void add_share_group_context(TestWebGraphicsContext3D* context3d) {
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index 5be1b46..9c968bd 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -10188,6 +10188,42 @@ TEST_F(LayerTreeHostImplTest, GpuRasterizationStatusModes) {
   EXPECT_TRUE(host_impl_->use_gpu_rasterization());
 }
 
+class MsaaIsSlowLayerTreeHostImplTest : public LayerTreeHostImplTest {
+ public:
+  void CreateHostImplWithMsaaIsSlow(bool msaa_is_slow) {
+    LayerTreeSettings settings = DefaultSettings();
+    settings.gpu_rasterization_enabled = true;
+    settings.gpu_rasterization_msaa_sample_count = 4;
+    auto context_provider = TestContextProvider::Create();
+    context_provider->UnboundTestContext3d()->SetMaxSamples(4);
+    context_provider->UnboundTestContext3d()->set_msaa_is_slow(msaa_is_slow);
+    auto msaa_is_normal_output_surface =
+        FakeOutputSurface::Create3d(context_provider);
+    EXPECT_TRUE(
+        CreateHostImpl(settings, std::move(msaa_is_normal_output_surface)));
+  }
+};
+
+TEST_F(MsaaIsSlowLayerTreeHostImplTest, GpuRasterizationStatusMsaaIsSlow) {
+  // Ensure that without the msaa_is_slow cap we raster unsuitable content with
+  // msaa.
+  CreateHostImplWithMsaaIsSlow(false);
+  host_impl_->SetHasGpuRasterizationTrigger(true);
+  host_impl_->SetContentIsSuitableForGpuRasterization(false);
+  EXPECT_EQ(GpuRasterizationStatus::MSAA_CONTENT,
+            host_impl_->gpu_rasterization_status());
+  EXPECT_TRUE(host_impl_->use_gpu_rasterization());
+
+  // Ensure that with the msaa_is_slow cap we don't raster unsuitable content
+  // with msaa.
+  CreateHostImplWithMsaaIsSlow(true);
+  host_impl_->SetHasGpuRasterizationTrigger(true);
+  host_impl_->SetContentIsSuitableForGpuRasterization(false);
+  EXPECT_EQ(GpuRasterizationStatus::OFF_CONTENT,
+            host_impl_->gpu_rasterization_status());
+  EXPECT_FALSE(host_impl_->use_gpu_rasterization());
+}
+
 // A mock output surface which lets us detect calls to ForceReclaimResources.
 class MockReclaimResourcesOutputSurface : public FakeOutputSurface {
  public: