Add BACKGROUND dump mode to various GPU/CC MemoryDumpProviders

cc/tiles/gpu_image_decode_controller.cc

Index: cc/tiles/gpu_image_decode_controller.cc
diff --git a/cc/tiles/gpu_image_decode_controller.cc b/cc/tiles/gpu_image_decode_controller.cc
index 7ce94b16f7a991e98fb12a9195fea1bc446048a4..6a0068bd5edb522cfcec2a07f11c70b588ffa958 100644
--- a/cc/tiles/gpu_image_decode_controller.cc
+++ b/cc/tiles/gpu_image_decode_controller.cc
@@ -548,8 +548,25 @@ void GpuImageDecodeController::SetShouldAggressivelyFreeResources(
 bool GpuImageDecodeController::OnMemoryDump(
     const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* pmd) {
+  using base::trace_event::MemoryAllocatorDump;
+  using base::trace_event::MemoryAllocatorDumpGuid;
+  using base::trace_event::MemoryDumpLevelOfDetail;
+
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("cc.debug"),
                "GpuImageDecodeController::OnMemoryDump");
+
+  if (args.level_of_detail == MemoryDumpLevelOfDetail::BACKGROUND) {
+    std::string dump_name =
+        base::StringPrintf("cc/image_memory/controller_0x%" PRIXPTR,
+                           reinterpret_cast<uintptr_t>(this));
+    MemoryAllocatorDump* dump = pmd->CreateAllocatorDump(dump_name);
+    dump->AddScalar(MemoryAllocatorDump::kNameSize,
+                    MemoryAllocatorDump::kUnitsBytes, bytes_used_);
+
+    // Early out, no need for more detail in a BACKGROUND dump.
+    return true;
+  }
+
   for (const auto& image_pair : persistent_cache_) {
     const ImageData* image_data = image_pair.second.get();
     const uint32_t image_id = image_pair.first;
@@ -559,41 +576,40 @@ bool GpuImageDecodeController::OnMemoryDump(
       std::string discardable_dump_name = base::StringPrintf(
           "cc/image_memory/controller_0x%" PRIXPTR "/discardable/image_%d",
           reinterpret_cast<uintptr_t>(this), image_id);
-      base::trace_event::MemoryAllocatorDump* dump =
+      MemoryAllocatorDump* dump =
           image_data->decode.data()->CreateMemoryAllocatorDump(
               discardable_dump_name.c_str(), pmd);
-      // If our image is locked, dump the "locked_size" as an additional column.
+      // If our image is locked, dump the "locked_size" as an additional
+      // column.
       // This lets us see the amount of discardable which is contributing to
       // memory pressure.
       if (image_data->decode.is_locked()) {
-        dump->AddScalar("locked_size",
-                        base::trace_event::MemoryAllocatorDump::kUnitsBytes,
+        dump->AddScalar("locked_size", MemoryAllocatorDump::kUnitsBytes,
                         image_data->size);
       }
     }
 
-    // If we have an uploaded image (that is actually on the GPU, not just a CPU
+    // If we have an uploaded image (that is actually on the GPU, not just a
+    // CPU
     // wrapper), upload it here.
     if (image_data->upload.image() &&
         image_data->mode == DecodedDataMode::GPU) {
       std::string gpu_dump_name = base::StringPrintf(
           "cc/image_memory/controller_0x%" PRIXPTR "/gpu/image_%d",
           reinterpret_cast<uintptr_t>(this), image_id);
-      base::trace_event::MemoryAllocatorDump* dump =
-          pmd->CreateAllocatorDump(gpu_dump_name);
-      dump->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
-                      base::trace_event::MemoryAllocatorDump::kUnitsBytes,
-                      image_data->size);
+      MemoryAllocatorDump* dump = pmd->CreateAllocatorDump(gpu_dump_name);
+      dump->AddScalar(MemoryAllocatorDump::kNameSize,
+                      MemoryAllocatorDump::kUnitsBytes, image_data->size);
 
-      // Create a global shred GUID to associate this data with its GPU process
+      // Create a global shred GUID to associate this data with its GPU
+      // process
       // counterpart.
       GLuint gl_id = skia::GrBackendObjectToGrGLTextureInfo(
                          image_data->upload.image()->getTextureHandle(
                              false /* flushPendingGrContextIO */))
                          ->fID;
-      base::trace_event::MemoryAllocatorDumpGuid guid =
-          gl::GetGLTextureClientGUIDForTracing(
-              context_->ContextSupport()->ShareGroupTracingGUID(), gl_id);
+      MemoryAllocatorDumpGuid guid = gl::GetGLTextureClientGUIDForTracing(
+          context_->ContextSupport()->ShareGroupTracingGUID(), gl_id);
 
       // kImportance is somewhat arbitrary - we chose 3 to be higher than the
       // value used in the GPU process (1), and Skia (2), causing us to appear