Add support for GPU acceleration in headless Chromium for Linux

Bug: 617551, 765284
Test: headless_shell --use-gl=egl

Change-Id: Id35866d675bac896aa73cca48e479b5b1efdee38
Reviewed-on: https://chromium-review.googlesource.com/c/1474442Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Joone Hur <joone.hur@intel.com>
Cr-Commit-Position: refs/heads/master@{#637081}

content/browser/gpu/gpu_data_manager_impl_private.cc

@@ -585,12 +585,14 @@ void GpuDataManagerImplPrivate::AppendGpuCommandLine(
 
 #if !defined(OS_MACOSX)
   // MacOSX bots use real GPU in tests.
-  if (browser_command_line->HasSwitch(
-          switches::kOverrideUseSoftwareGLForTests) ||
-      browser_command_line->HasSwitch(switches::kHeadless)) {
-    // TODO(zmo): We should also pass in kUseGL here.
-    // See https://crbug.com/805204.
-    command_line->AppendSwitch(switches::kOverrideUseSoftwareGLForTests);
+  if (browser_command_line->HasSwitch(switches::kHeadless)) {
+    if (command_line->HasSwitch(switches::kUseGL)) {
+      use_gl = command_line->GetSwitchValueASCII(switches::kUseGL);
+      // Don't append kOverrideUseSoftwareGLForTests when we need to enable GPU
+      // hardware for headless chromium.
+      if (use_gl != gl::kGLImplementationEGLName)
+        command_line->AppendSwitch(switches::kOverrideUseSoftwareGLForTests);
+    }
   }
 #endif  // !OS_MACOSX
 }

headless/lib/headless_content_main_delegate.cc

@@ -124,7 +124,16 @@ bool HeadlessContentMainDelegate::BasicStartupComplete(int* exit_code) {
   command_line->AppendSwitchASCII(::switches::kOzonePlatform, "headless");
 #endif
 
-  if (!command_line->HasSwitch(::switches::kUseGL)) {
+  if (command_line->HasSwitch(::switches::kUseGL)) {
+    std::string use_gl = command_line->GetSwitchValueASCII(switches::kUseGL);
+    if (use_gl != gl::kGLImplementationEGLName) {
+      // Headless uses a software output device which will cause us to fall back
+      // to software compositing anyway, but only after attempting and failing
+      // to initialize GPU compositing. We disable GPU compositing here
+      // explicitly to preempt this attempt.
+      command_line->AppendSwitch(::switches::kDisableGpuCompositing);
+    }
+  } else {
     if (!browser_->options()->gl_implementation.empty()) {
       command_line->AppendSwitchASCII(::switches::kUseGL,
                                       browser_->options()->gl_implementation);
@@ -133,12 +142,6 @@ bool HeadlessContentMainDelegate::BasicStartupComplete(int* exit_code) {
     }
   }
 
-  // Headless uses a software output device which will cause us to fall back to
-  // software compositing anyway, but only after attempting and failing to
-  // initialize GPU compositing. We disable GPU compositing here explicitly to
-  // preempt this attempt.
-  command_line->AppendSwitch(::switches::kDisableGpuCompositing);
-
   content::Profiling::ProcessStarted();
 
   SetContentClient(&content_client_);