Remember if GPU access was disabled by fallback

Set a bit in GpuDataManagerImplPrivate::FallBackToNextGpuMode() to
remember that the hardware acceleration was disabled by fallback, and
add a new error message in GpuAccessAllowed() to account for it. This
branch could be hit if the GPU process crashed repeatedly, and
SwiftShader was not available as a fallback option.

Bug: 986819
Change-Id: I93e2c08900b308e5897b3068053d7704324048ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1714811Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Sean Gilhuly <sgilhuly@chromium.org>
Cr-Commit-Position: refs/heads/master@{#680053}

content/browser/gpu/gpu_data_manager_impl_private.cc

@@ -359,6 +359,8 @@ bool GpuDataManagerImplPrivate::GpuAccessAllowed(std::string* reason) const {
           if (base::CommandLine::ForCurrentProcess()->HasSwitch(
                   switches::kDisableGpu))
             *reason += "through commandline switch --disable-gpu.";
+          else if (hardware_disabled_by_fallback_)
+            *reason += "due to frequent crashes.";
           else
             *reason += "in chrome://settings.";
         }
@@ -904,6 +906,7 @@ void GpuDataManagerImplPrivate::FallBackToNextGpuMode() {
 #else
   switch (gpu_mode_) {
     case gpu::GpuMode::HARDWARE_ACCELERATED:
+      hardware_disabled_by_fallback_ = true;
       DisableHardwareAcceleration();
       break;
     case gpu::GpuMode::SWIFTSHADER:

content/browser/gpu/gpu_data_manager_impl_private.h

@@ -201,6 +201,9 @@ class CONTENT_EXPORT GpuDataManagerImplPrivate {
   // What the gpu process is being run for.
   gpu::GpuMode gpu_mode_ = gpu::GpuMode::HARDWARE_ACCELERATED;
 
+  // Used to tell if the gpu was disabled due to process crashes.
+  bool hardware_disabled_by_fallback_ = false;
+
   // We disable histogram stuff in testing, especially in unit tests because
   // they cause random failures.
   bool update_histograms_ = true;