Add documentation for filing a memory bug on desktop.

Bug: 801006
Change-Id: If04968c66cf755cff0b892a5230d77ca6808a2a9
Reviewed-on: https://chromium-review.googlesource.com/935721Reviewed-by: Primiano Tucci <primiano@chromium.org>
Commit-Queue: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539149}

docs/memory/README.md

@@ -34,6 +34,11 @@ instead.
 | crbug [Stability=Memory](https://bugs.chromium.org/p/chromium/issues/list?can=2&q=Stability%3DMemory) label | Tracks mostly OOM crashes. |
 
 
+## I have memory problem, what do I do?
+
+Follow [these instructions](/docs/memory/filing_memory_bugs.md) to file a high
+quality bug.
+
 ## I have a reproducible memory problem, what do I do?
 
 Yay! Please file a [memory

docs/memory/filing_memory_bugs.md

+# Filing Memory Bugs
+
+This page describes the common set of steps for filing a memory bug.
+
+1. Grab platform-specific measurements.
+    * [macOS](#macOS)
+    * [Windows](#Windows)
+    * [Linux](#Linux)
+2. Grab a [memory-infra](#memory-infra) trace.
+3. [File a
+   bug](https://bugs.chromium.org/p/chromium/issues/entry?template=Memory%20usage)
+   on crbug.com. Attach screenshots and traces from previous steps.
+
+## Windows
+
+### Task Manager
+
+* Open Task Manager.
+* Select the **Details** pane.
+* Right click the first row with column names. Select **Select Columns**.
+    * Select **Memory (private working set)**
+    * Select **Memory (shared working set)**
+    * Select **Commit size**
+* Sort processes with highest **Memory (private working set)** first by clicking
+  once on the column name.
+* Take a screenshot using [Snipping
+  Tool](https://support.microsoft.com/en-us/help/13776/windows-use-snipping-tool-to-capture-screenshots)
+
+![Task Manager View](https://storage.googleapis.com/chromium-docs.appspot.com/memory_windows_task_manager.png)
+
+## macOS
+
+### Step 1 - Activity Monitor
+
+* Open Activity Monitor, Select the Memory Tab.
+* Under the **View** Menu, select the **Real Private Memory** and **Real Memory** columns.
+* Sort processes with highest **Private Memory** first by clicking once on **Private Memory**.
+* Take a screenshot by pressing cmd + shift + 3.
+* You can also use cmd + shift + 4 to manually select a region on the screen to save.
+
+![Activity Monitor View](https://storage.googleapis.com/chromium-docs.appspot.com/memory_macos_activity_monitor.png)
+
+### Step 2 - Terminal
+
+* Open the Terminal application.
+* Run the following command and report the results. ```vm_stat```
+
+![Terminal View](https://storage.googleapis.com/chromium-docs.appspot.com/memory_macos_terminal_vmstat.png)
+
+## Linux
+
+### /proc/meminfo
+
+* Open a shell.
+* Run the command ```cat /proc/meminfo```
+* Record the results.
+
+![Terminal View](https://storage.googleapis.com/chromium-docs.appspot.com/memory_linux_meminfo.png)
+
+## <a name="memory-infra"></a> Memory-Infra Trace
+
+* Open a new chrome tab and navigate to **chrome://tracing**
+* Click **Record** in the top left corner.
+* Click the button **Manually select settings** and click **None** under the left column to unselect everything.
+* Under the right column, select **memory-infra**
+* Click **Record**. Wait for five seconds. Then click **stop**.
+* Click the **Save** button in the top left corner a pick a name for the trace.