Add a "Max. MSAA samples" entry to chrome://gpu.

BUG=474727

Review URL: https://codereview.chromium.org/1063233002

Cr-Commit-Position: refs/heads/master@{#324236}

content/browser/gpu/gpu_internals_ui.cc

@@ -154,6 +154,8 @@ base::DictionaryValue* GpuInfoAsDictionaryValue() {
                                              gpu_info.pixel_shader_version));
   basic_info->Append(NewDescriptionValuePair("Vertex shader version",
                                              gpu_info.vertex_shader_version));
+  basic_info->Append(NewDescriptionValuePair("Max. MSAA samples",
+                                             gpu_info.max_msaa_samples));
   basic_info->Append(NewDescriptionValuePair("Machine model name",
                                              gpu_info.machine_model_name));
   basic_info->Append(NewDescriptionValuePair("Machine model version",

content/common/gpu/gpu_messages.h

@@ -166,6 +166,7 @@ IPC_STRUCT_TRAITS_BEGIN(gpu::GPUInfo)
   IPC_STRUCT_TRAITS_MEMBER(driver_date)
   IPC_STRUCT_TRAITS_MEMBER(pixel_shader_version)
   IPC_STRUCT_TRAITS_MEMBER(vertex_shader_version)
+  IPC_STRUCT_TRAITS_MEMBER(max_msaa_samples)
   IPC_STRUCT_TRAITS_MEMBER(machine_model_name)
   IPC_STRUCT_TRAITS_MEMBER(machine_model_version)
   IPC_STRUCT_TRAITS_MEMBER(gl_version)

gpu/config/gpu_info.cc

@@ -79,6 +79,7 @@ void GPUInfo::EnumerateFields(Enumerator* enumerator) const {
     std::string driver_date;
     std::string pixel_shader_version;
     std::string vertex_shader_version;
+    std::string max_msaa_samples;
     std::string machine_model_name;
     std::string machine_model_version;
     std::string gl_version_string;
@@ -135,6 +136,7 @@ void GPUInfo::EnumerateFields(Enumerator* enumerator) const {
   enumerator->AddString("driverDate", driver_date);
   enumerator->AddString("pixelShaderVersion", pixel_shader_version);
   enumerator->AddString("vertexShaderVersion", vertex_shader_version);
+  enumerator->AddString("maxMsaaSamples", max_msaa_samples);
   enumerator->AddString("glVersion", gl_version);
   enumerator->AddString("glVendor", gl_vendor);
   enumerator->AddString("glRenderer", gl_renderer);

gpu/config/gpu_info.h

@@ -138,6 +138,10 @@ struct GPU_EXPORT GPUInfo {
   // The version of the vertex shader used by the gpu.
   std::string vertex_shader_version;
 
+  // The maximum multisapling sample count, either through ES3 or
+  // EXT_multisampled_render_to_texture MSAA.
+  std::string max_msaa_samples;
+
   // The machine model identifier. They can contain any character, including
   // whitespaces.  Currently it is supported on MacOSX and Android.
   // Android examples: "Naxus 5", "XT1032".

gpu/config/gpu_info_collector.cc

@@ -12,6 +12,7 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
+#include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_context.h"
@@ -101,6 +102,9 @@ CollectInfoResult CollectGraphicsInfoGL(GPUInfo* gpu_info) {
   gpu_info->gl_extensions = GetGLString(GL_EXTENSIONS);
   gpu_info->gl_version = GetGLString(GL_VERSION);
   std::string glsl_version_string = GetGLString(GL_SHADING_LANGUAGE_VERSION);
+  GLint max_samples = 0;
+  glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
+  gpu_info->max_msaa_samples = base::StringPrintf("%d", max_samples);
 
   gfx::GLWindowSystemBindingInfo window_system_binding_info;
   if (GetGLWindowSystemBindingInfo(&window_system_binding_info)) {
@@ -141,6 +145,8 @@ void MergeGPUInfoGL(GPUInfo* basic_gpu_info,
       context_gpu_info.pixel_shader_version;
   basic_gpu_info->vertex_shader_version =
       context_gpu_info.vertex_shader_version;
+  basic_gpu_info->max_msaa_samples =
+      context_gpu_info.max_msaa_samples;
   basic_gpu_info->gl_ws_vendor = context_gpu_info.gl_ws_vendor;
   basic_gpu_info->gl_ws_version = context_gpu_info.gl_ws_version;
   basic_gpu_info->gl_ws_extensions = context_gpu_info.gl_ws_extensions;

gpu/config/gpu_info_unittest.cc

@@ -19,6 +19,7 @@ TEST(GPUInfoBasicTest, EmptyGPUInfo) {
   EXPECT_EQ(gpu_info.driver_date, "");
   EXPECT_EQ(gpu_info.pixel_shader_version, "");
   EXPECT_EQ(gpu_info.vertex_shader_version, "");
+  EXPECT_EQ(gpu_info.max_msaa_samples, "");
   EXPECT_EQ(gpu_info.gl_version, "");
   EXPECT_EQ(gpu_info.gl_vendor, "");
   EXPECT_EQ(gpu_info.gl_renderer, "");